Evidence from criminal law experts in Indonesian criminal trials: Usurping the judicial function?

Abstract

This article seeks to account for the recent explosion in the use of expert legal evidence given by criminal law academics in criminal trials in Indonesia. This issue has received almost no scholarly attention, despite experts sometimes even opining on the guilt or innocence of defendants. Focusing on the evidence given for criminal trials by three preeminent Indonesian legal scholars, this article examines the form and content of the evidence, the justifications put forward in Indonesia for allowing it, and whether judges are receptive to it. Contrary to the assumptions of lawyers, we find that, overall, expert evidence appears to have very little discernible impact on judicial decision-making. It does, however, give the state an evidentiary advantage over defendants in some cases. We then consider what our findings say about the Indonesian judicial system—particularly the perceived competence of its judges—and the legal system more broadly.

Introduction

In the past decade or two, a conspicuous trend has emerged in Indonesian legal proceedings: the increased use of expert evidence given by legal experts, often academics or former judges. These experts, usually called by the parties but sometimes by presiding judges, identify and explain the law they think is relevant to the proceedings. They sometimes even explain how they think the law should be applied in those proceedings. Often the experts testify in person, but sometimes the court appears to rely on a written statement an expert has produced.

This practice has been conspicuous in recent cases that have attracted widespread domestic and international attention. For example, in the criminal blasphemy trial of former Jakarta governor Basuki Tjahaja Purnama, ¹ the prosecution called one criminal law and three Islamic law experts, while the defence called four criminal law and two Islamic law experts. In the murder trial of Jessica Wongso, ² prosecutors called a criminal law expert and a criminologist, and the defence three criminal law experts. In high-stakes cases, lawyers seem to race to retain the higher-profile senior experts to support the positions of their clients or to produce more experts than their opponents. They seem to assume that either strategy will help, because judges will be persuaded by the testimony of well-known experts (especially if the experts are judges’ former university professors) or will simply follow the weight of the expert evidence. Even in run-of-the-mill cases, each side might call one or two legal experts.

Using expert evidence to identify and explain the law seems to reflect poorly on Indonesian judicial quality, particularly where that evidence goes so far as to suggest how that law should be applied in a given case. Using experts for these purposes is unnecessary if judges know the law and how to apply it. Worse, if judges rely on such evidence, legal experts seem to usurp the core judicial functions of objectively identifying the relevant law and then applying it to the facts proven during proceedings.

In other countries, for these and other reasons, having legal experts testify about the content of the law is contentious. Written expert reports or oral testimonies that express legal opinions—on the meaning of a domestic statute or judicial decision, or whether specific conduct violates the law, for example—may be ignored, redacted, or excluded as inadmissible (World Bank, 2010: 17). ³ Evidence going to the application of that law is even more likely to be excluded.

A significant enabling factor in the proliferating use of legal experts in Indonesian proceedings is that the law on expert evidence—relating, for example, to who can give it and for what purposes—is underdeveloped. In particular, no law covers whether legal experts can give evidence about the content of the law. There is very little discussion in legal circles, including among judges and scholars, about whether using expert legal evidence is problematic and should be limited. ⁴ Even between lawyers, there appears to be almost no discussion, much less consensus, about what legal or strategic advantages might follow from obtaining or using expert testimony. In other words, there are no established legal principles or accepted views about what purposes expert evidence can or should be used to serve, much less achieve.

This article examines the effect that evidence from criminal law experts appears to have on criminal trials in Indonesia. Our analysis is based on a reading of 74 decisions available on the Indonesian Supreme Court's online database (https://putusan3.mahkamahagung.go.id/), many of which were corruption trials. Our focus is on how judges addressed the expert evidence in the part of their decision containing the judicial reasoning (pertimbangan hukum) and earlier sections containing the evidence produced by the parties (including statements) and adduced at trial (including summaries of testimony). ⁵ We selected these cases because they contain evidence from one of three prominent criminal law experts. We have anonymised them—as Expert 1, Expert 2 and Expert 3—for privacy reasons. But we emphasise that they are among Indonesia's finest criminal law academics and are highly respected, including by us. Their expertise and qualifications were not disputed in these decisions. Our intention is certainly not to criticise them for the content of this evidence or for providing it.

We focus on the form the expert evidence takes, what experts include in their evidence, and the extent to which judges are receptive to that evidence in criminal trials. We then consider what our findings say about the Indonesian judicial system and the legal system more broadly. We demonstrate that the form and content of expert evidence included in case transcripts, and the response of judges to that evidence in their reasoning, differ from case to case. In some cases, this evidence conveys surprisingly-basic descriptions of fundamental principles of criminal law, while in others the evidence covers more uncertain or complex areas of law. In almost all, the expert provides only his or her view on the content of the relevant criminal law. But, as mentioned, in a few, the expert describes how the law should apply—in a handful of extreme cases, even opining about the guilt or innocence of defendants.

Yet if parties use expert evidence as a strategy to attempt to tell judges how they should decide cases, this strategy often fails. Our research shows that judges do not always follow expert evidence, even from prominent experts. In many cases, courts decide against parties who have called them. And, even when judges do decide in favour of those parties, they rarely seem to follow the arguments of the experts, let alone admit doing so. This is difficult to reconcile with the significant amounts of money parties are rumoured to spend hiring experts and the court time allocated to hearing and considering expert evidence. ⁶ Our findings beg the question: why do parties use, and judges allow, evidence from criminal law experts in criminal trials? We offer answers to this question.

The article is structured as follows. We begin, in Part I, by analysing Indonesian law dealing with expert evidence, focusing on criminal cases, but also constitutional cases, where experts have, too, been commonly used. We then specifically consider whether Indonesian law permits the use of written statements or live testimony of criminal law experts about the content of criminal law and its potential application in criminal trials. We subsequently seek to account for the explosion in the use of expert evidence in Indonesia over the past two decades or so, and present some hypotheses that may explain why lawyers, and even judges, call or use it. As we argue there, the use of expert evidence in particular courts during specific periods might be more justifiable than in others.

In Part II, we examine the content of expert evidence on criminal law, using examples from our selected cases, and consider the judicial reception to that evidence in those cases. In Part III, we return to an important distinction between the two main forms expert evidence takes: written expert statements and testimonies given in court. As we demonstrate, some written statements made by legal experts used at trial are not produced for trial. Rather, they are made upon police request to aid their investigations. But they remain in the case file of evidence upon which prosecutors base their cases and judges make their decisions. For reasons we explain, this provides a significant (and unfair) evidentiary advantage to the prosecution at trial.

Part I: Indonesian law on expert evidence

The law on expert evidence is threadbare in Indonesia. Article 184 of the Code of Criminal Procedure (Kitab Undang-undang Hukum Acara Pidana, or KUHAP) establishes ‘expert explanations’ (keterangan ahli) as a type of ‘valid evidence’ (alat bukti yang sah) that can be used in criminal cases. Article 1(28) of the KUHAP defines ‘expert explanation’ as:

a statement given by a person who has special expertise about something that is needed to clarify [something] in a criminal case, for the purpose of the [trial] examination.

Article 1(28) does not specify whether an expert explanation can take the form of a stand-alone written statement or whether an expert must attend court to give (and then defend) that statement. However, Article 186 appears to implicitly require court attendance, stating that ‘expert explanations are what an expert says in court’. This suggests that what an expert says or writes is not an ‘expert explanation’ unless given in court. As discussed below in Part III, there is significant controversy about the evidentiary strength of written statements made by experts who do not attend trial. Despite Article 186, many Indonesian judges seem content to treat expert written statements alone as valid ‘expert explanations’.

The KUHAP refers to ‘forensic medical experts (ahli kedokteran kehakiman), doctors or other experts’ (Article 179(1)). In the interests of justice, these experts must, if requested, provide an expert explanation about ‘injury or poisoning or death’ that is suspected to have resulted from a crime (Elucidation, Article 133(1)). ⁷ The explanation must be ‘their best and true, according to knowledge in their area of expertise’ (Article 179(2)). ⁸ However, beyond this, the KUHAP neither specifically restricts who can be classified as an expert nor limits the subject matter about which an expert can testify, provided that they have sufficient knowledge to be deemed an expert. More specifically, there is no legal impediment to legal academics or practitioners being expert witnesses. Just as forensic scientists or medical doctors can be experts, so too, it seems, can legal academics with relevant knowledge or expertise. Apparently, this includes criminal law experts, who are not prohibited from giving evidence about their areas of expertise, including the content of substantive criminal law. Continuing the same logic, how the law is or should be applied can also fall within the expertise of criminal law experts who analyse cases (in which the law is applied) in their research or teaching.

The KUHAP does, however, specify two purposes for which expert evidence may be used. First, a presiding judge can request an expert explanation to ‘clarify an issue that arises during proceedings’ (Article 180(1)). There is, however, no requirement that the explanation be necessary in the sense that the explanation provides information otherwise unavailable to the court or that the judge needs the explanation to make the decision. Second, the defendant has a right to put forward witnesses or people with special expertise to provide explanations that are advantageous to him or her (Article 65). While neither the KUHAP nor any regulation known to us specifies that prosecutors can put forward experts at trial, they consider themselves to have the same right, and routinely exercise it.

Exclusion of expert evidence

The KUHAP contains no rules requiring the exclusion of evidence, including expert evidence, even where the reliability of the evidence or the expertise of the expert might be questionable. ⁹ This is not unusual in civil law countries, particularly where juries are not used and there is, therefore, no need to prevent unreliable evidence from affecting the decisions of laypersons (Merryman, 1985: 117). Indonesian judges generally consider themselves free to determine the precise weight, if any, they give to expert evidence, and how many experts should be heard. ¹⁰ But they need not follow even the most reliable or relevant expert evidence or give reasons for rejecting it (Qurata, 2014: 345, 350).

In constitutional cases, judges, parties and even related parties (pihak terkait) can call experts, ¹¹ whose explanations are also formally considered valid evidence. ¹² Unlike criminal cases (where, as discussed in Part III, the legal position is murky), in constitutional cases, experts must produce a written explanation and appear before the court. ¹³ A 2005 Constitutional Court Regulation defined expert explanations as:

explanations given by a person who, because of his or her education and/or experience, has expertise or deep knowledge that relates to the [constitutional claim], in the form of an opinion that is scholarly, technical or another special opinion about a piece of evidence or a fact that is needed for the examination of the claim. ¹⁴

Unlike other judges, Constitutional Court judges also have express power to assess the relevance and competence of experts whose evidence they receive. ¹⁵ Although not spelt out in the Regulation, constitutional judges appear able to reject expert evidence if it is not relevant or the witness lacks the expertise to give the evidence. The Regulation also specifies that even if an expert fails to attend court to give evidence, the court can still consider that expert's explanation, after hearing from the party who called that witness. ¹⁶ Although again not clearly spelt out, this seems to allow judges to consider written expert statements even if the experts who wrote them do not attend court for examination.

We are not aware of any instance where an Indonesian court—criminal or constitutional—has excluded expert evidence for falling outside the claimed expertise of the expert. As discussed below, judges rarely even mention expert evidence in their verdicts. Indeed, we are not aware of instances where opposing parties or judges have even challenged an expert's expertise. Nevertheless, evidence from experts about something that falls outside their expertise will arguably no longer formally qualify as an ‘expert explanation’. In criminal matters, it would no longer be admissible evidence under Article 184 of the KUHAP, unless it could qualify as an ordinary witness statement. Although also a valid type of evidence, an ordinary witness statement can only convey what the witness heard, saw or experienced. ¹⁷ An expert witness will, except by some extraordinary coincidence, usually not have heard, seen or experienced anything relevant to the commission of the alleged crime to which proceedings relate. So, any opinion they convey beyond their expertise will not fall within this definition and, accordingly, judges should accord it no weight.

Even though judges and parties do not appear to reject or challenge an expert's level of expertise, it cannot be said that expertise is irrelevant. The qualifications and experience of each expert are always set out in their written statements and in summaries of their in-court testimony. This suggests that judges do—or at least could—consider the level of expertise and knowledge of those who give expert testimony when assessing the evidentiary weight of their evidence. Indeed, in some cases, experts have been called upon to explain their expertise. For example, in Wongso's trial, prosecutors asked Expert 1 about what he needed to achieve to be appointed professor of criminal law. ¹⁸ He explained that he had needed to master the ‘material’ and ‘formal’ aspects of criminal law, and to write books about criminal law. ¹⁹ Nevertheless, while the level of expertise appears relevant, precisely how it bears on judicial decisions is rarely specified in those decisions and, therefore, remains unclear. For example, Indonesian judicial verdicts never mention the relative experience of experts involved in the trial as a basis to prefer the evidence of one over the other.

Unlike in other countries, experts in Indonesia have no formal obligations or overriding duties to the court, ²⁰ and there is no law on contempt of court (Wiyono, 2015). Experts do not even appear to have a legal obligation to provide impartial evidence. Academic experts face no consequences for providing incorrect or inconsistent expert evidence, unlike prosecutors, ²¹ advocates, ²² and judges, ²³ who may be held to account for violating ethical standards. However, some commentators, including Expert 1 himself, have written that experts must be objective and driven only by their knowledge and ethics. According to Expert 1, ‘Just because an expert is called by an accused or defendant does not mean that the expert must blindly defend him or her’. ²⁴

Yet the perception remains in Indonesia, as elsewhere, that experts will provide evidence that favours the party that pays them (Riyanto, 2016). However, they do risk prosecution for perjury for giving plainly false evidence. Under Article 242(1) and (2) of the Criminal Code, any person who gives a false statement under oath, either orally or in writing, faces up to seven years’ imprisonment. If that statement is given in a criminal case and is damaging to the defendant, then the maximum term of imprisonment is nine years.

Legal proceedings against experts

To our knowledge, no experts have been prosecuted for giving deliberately false or misleading evidence. ²⁵ However, a handful have been sued by defendants for the evidence that they have given against them in criminal cases. The basis upon which these proceedings were brought is unclear, which suggests that they were spurious. One case involved evidence provided by criminal law expert Eva Achjani Zulfa. During their investigations into alleged fraud perpetrated by a suspect, Andy Tediardjo, police consulted with Zulfa about the strength of the evidence they had obtained against him. In a written statement, Zulfa indicated that, based on the evidence collected, Tediarjo had committed fraud, ²⁶ which led police to formally charge Tediarjo. Ultimately, Tediardjo was found not guilty, but he sued Zulfa in the Depok District Court for the advice she gave to the police. ²⁷ Tediardjo was unsuccessful, but the decision is not publicly available so we are unable to analyse it.

However, we can say that Indonesian courts appear reluctant to hold experts accountable for outcomes to which their explanations might contribute. This seems clear from another case in which an academic was sued by former Governor of South Sulawesi Nur Alam for the evidence he gave against Alam in a corruption trial. ²⁸ Here, the expert was Basuki Wasis, from the Bogor Agricultural Institute (Institut Pertanian Bogor or IPB). Wasis was not a legal expert; his evidence related to the cause and extent of environmental destruction caused by mining that Alam had approved. ²⁹ Alam's civil suit against Wasis was dismissed, with the court finding that an expert's opinion in a civil or criminal trial could not form the basis for such legal action. This was because the defence could have objected to or refuted the opinion during the trial, including by calling its own experts, and, in any event, the presiding judges were ultimately responsible for determining whether to rely on the evidence presented (Riana, 2018). ³⁰

Why the increase?

As mentioned, with few exceptions, Indonesian legal scholars, lawyers and judges have raised few questions about the use of expert legal evidence. Unsurprisingly, then, the apparent increase in the use of legal expert witnesses in legal proceedings has drawn little attention or criticism. Indeed, we are unaware of any scholarly or other attempt to explain that increase. In this section, we offer some potential (but speculative) explanations, based on our observations.

There is no basis upon which to claim that Indonesia's predilection for expert evidence is inherited. The Dutch, who colonised parts of the archipelago for over 300 years, left behind the civil law tradition and Indonesia's legal backbone, including civil and criminal codes. Like Indonesian law, Dutch law permits the use of expert evidence in proceedings. ³¹ But Netherlands’ courts do not permit legal experts to give evidence of national (Dutch) law—they only allow expert evidence about the content of foreign law. ³²

In our observation, legal expert evidence appeared to become commonplace after the Constitutional Court was established in 2003, ³³ five years after the end of Soeharto's authoritarian regime. During this five-year period, Indonesia put in place components of a constitutional democracy. Central to this was an overhaul of the 1945 Constitution, which took place over four annual rounds from 1999 (Indrayana, 2008). Among the reforms was the insertion, in 2000, of a catalogue of constitutional rights.

When the Constitutional Court began operating, only a handful of Indonesians had sufficient knowledge and ability to adjudicate constitutional cases, which were entirely new to Indonesia. The primary candidates for appointment to the court were—as they remain today—former politicians, judges serving on other courts, and academics. However, very few were obviously suitable. Most experienced politicians had spent most of their political careers working within an authoritarian setting in which there was no culture of effective checks and balances, such as those offered by constitutional review. ³⁴ As for judges, very few had ever reviewed laws. For decades, the Supreme Court had possessed powers of regulatory review, under which its judges examined regulatory instruments for consistency with national statutes. Supreme Court judges had avoided wielding these powers where possible, apparently through fear of government reprisal. No judges had had the power to engage in the higher-stakes endeavour of reviewing national statutes for constitutional compliance. Some of the Supreme Court judges who were appointed to the Constitutional Court acknowledged this lack of experience. ³⁵

Academia also offered slim pickings. When the court was established, constitutional law was among the least developed fields of Indonesian law. Indonesia had virtually no constitutional jurisprudence. While successive authoritarian regimes had sought political legitimacy by claiming to govern under the 1945 Constitution, that document provided neither citizens’ rights nor judicial review. ³⁶ One consequence was that Indonesian constitutional law was an arid academic endeavour, with no content beyond the Constitution's text and the debates that shaped its drafting and promulgation. There was certainly very little scope for argument about interpretations of the document that diverged from those pushed by the regime. Only a handful of constitutional law scholars worked to overcome this barren intellectual environment. But most of them were close to retirement age. Fortunately, there was one exception—Professor Jimly Asshiddiqie—who became the court's first chief justice.

The result was that, Asshiddiqie aside, most founding Constitutional Court justices had limited knowledge and expertise with which to adjudicate cases arising from Indonesia's expanded Constitution. These included cases that required them to delineate the scope of the new constitutional rights. In the face of a significant caseload and time pressure, both the court and the parties began calling international and domestic experts to help them understand the potential interpretations of constitutional rights, often drawing on comparative and international perspectives. ³⁷ Constitutional Court judgments always included the testimony the experts gave, and the court sometimes engaged with that testimony in its reasoning. ³⁸

However, lack of knowledge and expertise probably only partly explains the Constitutional Court's early appetite for expert legal witness testimony. We speculate that using experts also helped the court pursue a desire to be a prominent site for open political and legal debate, which had not existed in Indonesia for many decades. The use of legal experts, particularly by opposing parties, meant that such legal debate could be well-informed and more likely to attract public (and media) attention, thereby helping develop widespread support for the court. Also, having multiple experts (legal or not) gave proceedings a participatory air, which the court—under the inspirational leadership of Jimly Asshiddiqie (Hendrianto, 2018)—was keen to foster.

Within a few years, the use of legal expert witnesses had spread to other courts. Why this happened is not entirely clear, but we speculate that many factors were at play. The general courts (which the Supreme Court administers) were, around the time the Constitutional Court was created, seeking to re-establish themselves as credible judicial institutions. Under the Soeharto regime, they had developed a reputation for being corrupt, subservient to government, untransparent, unaccountable and incompetent. In light of the early successes of the Constitutional Court and the respect it appeared to enjoy, we speculate that other Indonesian courts probably felt compelled to follow some of its transparency-enhancing practices, such as using experts. ³⁹ This was also a period of significant legal reform in Indonesia, and some judges may have found it difficult to keep up with the changes. Particularly in complex cases, they may have been receptive to expert legal evidence. From here, using legal experts appears to have become more mainstream, such that it is now routinely used, even in straightforward cases.

We suspect also that insistent lawyers, particularly those working on high-profile cases, have helped normalise using expert legal witnesses. In many conversations, lawyers have told us that, a particularly well-respected or eloquent expert might more persuasively convey legal arguments that support their clients than they can themselves, even if the lawyers have devised the arguments. Lawyers also explained that they called experts to support or even repeat arguments they had already made in submissions because they thought that judges might either have not read their submissions (but might listen to the expert) or be more receptive to these arguments than if presented by the lawyers only.

On a more basic level, some lawyers thought that judges might interpret the appearance of an expert as indicating that the expert supported their client's legal position. Here, lawyers seemed to presume that judges would be influenced by the expert's gravitas, regardless of the content of the expert's explanation. This was all the more likely if the expert worked as an academic from one of Indonesia's leading law schools, particularly if the presiding judges had attended that school. According to the lawyers, the ‘expert effect’ is amplified if numerous experts make the same or a similar point at trial, particularly if they are well known. The more experts a party can muster, the better, particularly if the opponent has fewer.

Indonesian justifications

While, as mentioned, the Indonesian legal literature on expert legal evidence is threadbare, a handful of writers have sought to justify its use to help judges understand the law. Some take a relatively narrow view, arguing that judges need it for new or complex areas of law—to help them avoid mistakes or even miscarriages of justice (Salmande, 2014). Others take a more expansive view, maintaining that expert legal evidence can be used even in run-of-the-mill cases heard by experienced judges. For example, Expert 1 has written:

Based on the ius curia novit adage, judges are considered to know the law, such that legal expert evidence is not necessary. However, in reality, in Indonesian court proceedings, expert evidence is still needed … [With] all due respect to judges, the intellectual capacity of many judges is insufficient …. [We don’t want] fundamental legal issues to be misunderstood. If this happens, then courts, which aim to discover the material truth about a legal event, will tend to be misguided because of a lack of complete understanding about the substance of the law. ⁴⁰

These justifications presume that expert evidence is the only reliable way for lawyers and judges to obtain the legal advice or assistance they need, or at least that it is a particularly efficient or effective way to obtain them. These are commonly held views in Indonesia. Indeed, well-regarded judges—including former Supreme Court Judge Paulus E. Lotulung and former administrative court judge Benjamin Mangkoedilaga—have publicly supported them (Pangaribuan, 2009: 388–89).

We argue that using expert legal evidence to provide advice or assistance to judges is undesirable in Indonesia—just as it is elsewhere—for at least two reasons. First, it contradicts the ius curia novit principle, which applies in Indonesia, as it does in many countries. ⁴¹ Under this principle, judges are considered to know and understand the law (and, presumably, how to identify and apply it in their cases). Of course, the ius curia novit principle is strictly speaking a fiction: it is practically impossible for any judge to already know all law. But if judges are unfamiliar with legal principles involved in the cases they hear, they can and must themselves examine the relevant legal material—legislation, regulations and even judicial decisions—to obtain the legal knowledge they need. In this endeavour, they can, if necessary, seek research assistance from their legal clerks and other staff. Rightly or wrongly, they might also consult their brethren, or even informally obtain advice from trusted sources.

Of course, taking these steps requires judges to recognise that they lack the legal knowledge their cases require. Harahap, a prominent Indonesian former Supreme Court judge and scholar, says that judges can tend towards ‘arrogance and recklessness’ if they consider themselves to know the law when in fact they do not (2005: 822). He says, for example, that many Indonesian judges have ‘extremely limited’ knowledge about the law relevant to international business transactions. Accordingly, he says:

Facing such circumstances, judges must discard their feelings of superiority, and be willing to accept the legal bases put forward by the parties so that the decision handed down does not deviate from the provisions and the spirit of the actual objective law (Harahap, 2005: 822).

Nevertheless, just because judges might need additional legal knowledge does not mean that they should get it from a legal expert witness, in public proceedings. Where they do so, they may betray lack of basic legal research skills. And, given that most experts are paid by a party, questions might legitimately be raised about whether the knowledge they impart favours that party, particularly given that experts have no overriding duty to the court, as discussed above. In short, relying on expert evidence for legal knowledge raises questions about judicial competence and objectivity.

The second reason why using legal expert evidence is undesirable is that it can ‘invade the province of the judge’ (Friedland, 1993: 454–55)—particularly where it involves identifying an applicable law that is contested or relates to the application of the law to the case at hand. These are both recognised as strictly judicial functions in Indonesia. According to Harahap, ‘determining and applying the objective law is not the right or responsibility of the parties, but falls within the absolute obligation and authority of the judge’ [our emphasis] (Harahap, 2005: 821). These functions are not for experts to perform. If judges follow these types of expert evidence, then they become susceptible to claims that judicial independence has been compromised.

As we shall see in Part II, our data do not clearly support many of the assumptions that judges and lawyers may make about the benefits of expert evidence, at least in criminal cases. In some decisions we examined, the expert legal evidence was rudimentary—even Indonesia's least experienced judges must certainly already have known the legal principles it outlined. Further, in many cases, judges simply ignored the views of experts; rarely, they even openly disagreed with those experts. In other words, while the use of experts certainly has the potential to intrude on the judicial role and is thought by many lawyers to give them an advantage, it appears to do neither.

Part II: Data and findings

As mentioned, we analysed 74 criminal cases, which we obtained from the Supreme Court's decision database. All these cases contained what appeared to be either the written statement of the expert witness, or a summary of the statement given by the expert at trial, or both. These constituted all cases available at the time of searching in January 2022 containing evidence (written or oral) of one of the three well-known criminal law experts mentioned above. We were able to obtain 43 cases in which Expert 1's expert evidence was reported. He has testified in many more cases than this (but none of them were available to us for review). This is clear from decisions in which he has presented evidence of his experience. In one 2012 case, he testified that he had given evidence in 50 cases, including in district courts, the Tax Court and the Constitutional Court. ⁴² By 2018, he claimed to have given evidence in over 200 cases, ⁴³ and by 2019 in over 250. ⁴⁴ Expert 2's evidence featured in 12 cases and Expert 3's in eight. We now turn to discuss our findings.

Descriptions of basic principles

Some expert statements in the cases resembled a transcribed introductory undergraduate law lecture, providing an overview of the criminal law relevant to the case. Most of these explanations were entirely descriptive; they did not appear designed to persuade judges of the legal position favouring the party who called the expert. Because the expert's coverage was so rudimentary, it cannot be said to have helped judges understand complex or new laws.

For example, Expert 2's explanation in one bribery case covered material suitable for introductory chapters of a criminal law textbook, mentioning law and legal concepts that the presiding anti-corruption court judges must certainly use in their daily work. For example, she described ‘elements’ (unsur) of crimes and noted that ‘if in a criminal case an element is not proven then we must say that there is no crime, but it is up to the judge whether to dismiss the case or to acquit the defendant’. ⁴⁵ She also noted that bribery cannot be committed by one person, but rather requires at least two—one as the giver of the bribe and the other as the receiver. ⁴⁶ In another case, she discussed the basic concept of ‘participation’ under Indonesian criminal law—again, an undergraduate-level topic covered in standard Indonesian criminal law textbooks. ⁴⁷

Similarly, Expert 3 provided elementary explanations about money laundering law in many of the cases in which he testified. In some cases, ⁴⁸ his explanation largely restated the contents of provisions of Indonesian money laundering legislation that judges could surely easily obtain and read themselves. In one case, he observed the foundational rule of Indonesian evidence law that convictions must be based on at least two pieces of valid evidence. ⁴⁹ Large parts of Expert 3's statement in this case sought to explain that a defendant could be found guilty of money laundering without a predicate crime having been proven first. ⁵⁰ This is not controversial under Indonesian law. As Expert 3 himself pointed out in this and other cases, Indonesian courts have consistently applied Article 69 of the Money Laundering Law, which clearly establishes this.

Indeed, in some cases, the experts conveyed information that can be found in textbooks they have written. ⁵¹ While this is perhaps unsurprising, one wonders why the judges were not already familiar with the basic concepts they covered or, if not, why the judges could not have consulted these texts themselves. For example, in at least six cases case, ⁵² Expert 1 outlined the very same 18 theories of intent that he outlined in his own book in very similar terms. In at least four others, he explained some of these 18 theories—including dolus malus, dolus directus, dolus premeditates, dolus alternativus, dolus repentinus—again adding nothing to his book's coverage. ⁵³ Expert 2 gave evidence about defences (specifically about noedtoestand and overmatch) ⁵⁴ which she has covered in her books. Similarly, in at least two cases, ⁵⁵ Expert 3's descriptions of the money laundering concepts of placement, layering and integration seemed to draw on his written work.

Some expert evidence was more technical. For example, in one corruption case, Expert 1 gave a several-page description of controversial components of Article 2 of the Corruption Law, particularly the concept of ‘unlawful act’ (and relevant Constitutional and Supreme Court decisions about the concept). ⁵⁶ Nevertheless, these controversies and concepts are well known (Butt, 2009; Sapardjaja, 2002). Many scholars have traversed them, and anti-corruption court judges regularly apply Article 2 (Hukumonline, 2016). While complex, these concepts would certainly already be entirely familiar to these judges.

Application of law to facts

As mentioned, a common objection to legal expert evidence is that it can usurp the judicial function, particularly if it suggests how the law should be applied to the case at hand. Expert 1 has expressed this objection in numerous cases. In one case, for example, he explained that an expert ‘is not permitted to enter into the case. Experts always refuse to do this, if asked about a concrete case’. ⁵⁷ In another, he explained:

an expert opinion should not be given [concerning] a concrete case… An expert's testimony should not arrive at a conclusion that says a defendant is guilty (and hence should be punished) or not (and hence should be acquitted). An expert can only give general and theoretical information. ⁵⁸

However, experts, including Expert 1 himself, routinely do precisely this, in a range of cases, including in the corruption, fraud and other cases that we now discuss.

Corruption cases

A 2012 corruption case provides a clear example of an expert explanation suggesting how the relevant law should be applied. In this case, several county parliament members were found to have misused their official allowances. ⁵⁹ The main allegations were that they used funds allocated for operational, medical and fuel expenses for improper purposes and had not provided expenditure receipts. While the local parliament had issued a regulation permitting these expenditures, prosecutors argued that the members were bound by national-level regulations that imposed financial accountability standards, including by requiring receipts.

Expert 1 was an expert witness for the prosecution. He was unable to attend the trial. ⁶⁰ But a statement made by Expert 1, which appears in the transcript, set out various national laws that the members appeared to have violated. He concluded:

If asked whether, according to the expert…the acts of the local parliament members who are defendants in this case have diverged from provisions [of the law] and whether the divergences from those provisions causing state loss fall within the domain of the criminal law, the expert answers: Yes, because those divergences clearly violate several rules…and those acts also fulfil the elements of a criminal offence as is contained in the Corruption Law… It is clear that the act…falls within the domain of criminal law. ⁶¹

Expert 1's evidence in this case addressed an important and controversial area of Indonesian corruption law—the point at which an act causing loss to the state moves from, on the one hand, being treated as either a mere consequence of a legitimate decision or an administrative oversight (which might attract only civil liability) to, on the other hand, become a criminal matter. In our view, the decision in this case turned on how this distinction was drawn—in other words, whether merely failing to provide receipts was an oversight or criminally culpable. Expert 1 favoured the latter interpretation, but, as a matter of law, this was for judges alone to decide.

In the same case, Expert 1 also asserted that whether a defendant's act in fact causes state loss is irrelevant: corruption occurs if the defendant meets the elements of the crime, including whether the act could have caused state loss, even if it did not. This might appear to be a description of accepted legal principle. But we suspect that Expert 1's statement was included to anticipate the counterargument that the defendants were entitled to the allowances, and so they caused no loss by merely failing to properly account for them. ⁶²

Expert 1 also seemed to tell a court how to decide another case in 2013. The defendant was a former university rector, prosecuted and ultimately convicted for misusing corporate social responsibility funds from a state-owned enterprise. ⁶³ This time, Expert 1 appeared for the defendant and testified at trial. He said:

The correct way to analyse a corruption case is: (1) Look at the facts as a whole. (2) Apply the facts into the formulation of the crime in the Corruption Law. (3) Analyse whether the act accords with the lawmakers’ intent such that the defendant is to be brought before the court… ⁶⁴

Expert 1 also said that, if more than one area of law could be applied to a set of facts, the ‘most dominant’ of them should prevail. So, if this matter was predominantly civil, then the civil law, not the criminal law, applied. ⁶⁵ The classification of acts as civil or criminal in corruption cases is another controversial area of Indonesian corruption law (Butt, 2012). On our reading, Expert 1's focus on discussing only the possibility that the act was civil implied that it was not criminal. But, how such acts are categorised in corruption cases is a matter of law, best left for judicial determination untainted by the views of an expert.

In 2019, a statement by Expert 1 was included in another corruption court decision. ⁶⁶ This statement appeared to be made to police during their investigations and includes a clear assertion of guilt, based on evidence that had not yet been presented—much less challenged—before a court. The statement included these words:

based on the chronology…conveyed by police, there is a conspiracy to commit corruption that damages state finances under [the Corruption Law and the Criminal Code]. ⁶⁷

We consider the significance of the use of police-obtained expert statements in judicial proceedings in Part III.

Fraud cases

Expert 1 provided evidence for the prosecution in a case involving an alleged violation of Indonesia's Forest Destruction Prevention and Eradication Law. ⁶⁸ The defendant was accused of producing and using timber transportation documents that misrepresented the source and legality of timber. After mentioning relevant provisions of that Law, Expert 1 declared that the defendant's acts ‘clearly’ ‘fulfilled the elements’ of those provisions. ⁶⁹ He continued that, based on the facts:

it cannot be doubted that [the company the defendant owned] must be held responsible…and criminal penalties for managers or others performing acts using the name of the corporation are the [defendant and another person]. ⁷⁰

Expert 1 appears to have effectively passed judgment on the defendant. He has also drawn a conclusion that ignored live legal controversies about pursuing corporations for criminal acts in Indonesia—particularly about whether they could be prosecuted at all (Muladi and Sulistyani, 2015). Similarly, in a case involving the forgery of fuel transportation documents, Expert 1 said that after viewing the police file of evidence, it was ‘very reasonable to suspect that the defendant's act was a criminal act that fulfilled the elements of [the Criminal Code]’. ⁷¹ Drawing conclusions of guilt in both fraud cases was premature, given that the facts upon which they were based had not been proved in court when the expert statement was made.

In another case, the defendant, a local parliamentarian, had allegedly procured several hundred false birth certificates. The defendant apparently hoped that recipients of the certificates would then use them to identify themselves on polling day and vote to re-elect him. ⁷² Expert 1 explained the elements of document fraud under the Criminal Code provisions. ⁷³ He concluded:

Based on the chronology of events mentioned above, the expert can ascertain that the birth certificates created by [another person] on the request of [the defendant] are fraudulent documents, because they were validified by a person without authority or not in accordance with procedures. In short, the act [met the requirements of the crime of] document fraud. ⁷⁴

Other cases

In another case that includes a statement by Expert 1, the defendant was a member of a group accused of killing a person who the defendant thought would imminently steal his motorbike. Based on information police investigators gave him, Expert 1 opined that ‘the act of the defendant [and others]…was a criminal act’, which violated Articles 170(1)–(3) of the Criminal Code. ⁷⁵ In arriving at this view, he said that self-defence did not apply:

according to the expert, what the defendant did cannot be categorised as…self defence because the strength of the victim compared to the strength of the defendant was not balanced—even though the victim was powerless, the defendant allowed the continuation of violence experienced by the victim. ⁷⁶

Expert 1 was not the only expert to offer evidence that intruded into the judicial domain in our cases. For example, in one decision a statement from Expert 3 listed versions of Indonesia's national money laundering statute—which has been amended several times—and then determined which one of them applied to the case at hand, based on the timing of the alleged offences. ⁷⁷ Of course, judges should exclusively identify the law relevant to cases over which they preside.

Judicial receptiveness to expert arguments

Our cases did not provide much evidence of judges being swayed by expert explanations. This was surprising, given the widespread use of experts and the significant fees they are said to collect for giving evidence, discussed above. Expert evidence was mentioned in less than half of the judicial reasoning sections of our cases. For example, courts referred to Expert 1's evidence in only 14 of the 43 cases in which his evidence appeared. ⁷⁸ Of Expert 2's 12 cases, the court addressed her testimony in only six cases. ⁷⁹ The court addressed Expert 3's evidence in only two of the eight cases in which his evidence appeared.

Even in the cases where courts did mention expert explanations, the courts did not articulate the weight attributed to the explanations, if any. Rather, the courts mentioned expert explanations in passing, without clearly indicating approval or disapproval.

Judicial rejection of legal expert evidence

In no cases did the court expressly follow or adopt the evidence of any of our three experts (although it did follow the evidence of another expert, as discussed below). The judges did expressly disagree with expert opinions. But this was rare, occurring in only two of our cases.

In the first case, the Serang District Court disagreed with Expert 1's testimony. ⁸⁰ This was a corruption case in which the defendant, the managing director of a private company, was found guilty of causing loss to the state. The controversy arose from his dealings with a foundation (yayasan) established by the state-owned steel company to manage its employees’ health fund. A central issue was whether the foundation's finances could be classified as ‘state finances’, such that any loss to the foundation’s finances caused by the defendant's acts were ‘losses to state finances’. This was important because one element of the corruption law provision under which he was indicted required prosecutors to prove ‘loss to state finances’. ⁸¹ If the foundation's finances were indistinguishable from the state-owned steel company's finances, then the defendant's act would satisfy this element; if they were not, then he could not be convicted under that provision.

Whether the assets of a subsidiary of a state-owned enterprise comprise the assets of the state-owned enterprise itself has long been an issue of genuine legal debate in Indonesia. Expert 1 was called by the defence. ⁸² He propounded the view that the finances of a subsidiary of a state-owned enterprise—here, the foundation—could only be classified as state finances if the subsidiary's initiating capital came directly from the state budget (a defining legal characteristic of a state-owned enterprise). ⁸³ If, instead, the subsidiary was established using capital from the parent state-owned enterprise, some other source or a combination of sources, then its finances were not state finances. To reach this conclusion, Expert 1 referred to two superior court decisions: one of the Constitutional Court ⁸⁴ and another from the Supreme Court (in which the same Constitutional Court decision was followed). ⁸⁵

The judges disagreed, finding that the subsidiary's finances were state finances, even though the subsidiary had not been established using funds taken directly from the state budget. In finding the defendant guilty of corruption for causing loss to state finances, the judges acknowledged following the views of another criminal law academic who had provided an expert opinion in the case. ⁸⁶ The judges emphasised the close relationship between the state-owned steel company and the foundation to support its findings that the foundation's finances were state finances. Elements of this relationship included that the foundation was required to report its financial performance to the company; that the foundation's contributions came from company employees; that the directors of the company were also managers of the foundation; and that the foundation was established to fulfil the legal obligations of the company to its employees. ⁸⁷ The judges also pointed to the Corruption Eradication Law which, in the words of the court:

clearly and firmly states that State Finance is all of the property/resources of the state in any form, separated or not, including all parts of the property and resources of the state and all rights and obligations that arise because the assets are under control, management and responsibility, including of a Foundation. ⁸⁸

In reaching that conclusion, the Serang District Court was careful to distinguish the present case from the Constitutional Court decision Expert 1 cited. That Constitutional Court case was a challenge to the result of the 2019 presidential election brought by the unsuccessful presidential and vice-presidential candidate pair Prabowo Subianto and Sandiaga Salahuddin Uno. ⁸⁹ The successful vice-presidential candidate, Ma’ruf Amin, had been listed on the websites of two banks—BNI Syariah and Bank Syariah Mandiri—as chair of their respective Syariah Compliance Boards. Subianto and Uno argued that these banks were state-owned enterprises, making Amin ineligible for election. ⁹⁰ The Constitutional Court found that each bank was a subsidiary of a state-owned entity and a private company. ⁹¹ However, the two banks themselves were not state-owned entities because their initiating capital did not come directly from the state budget. ⁹² As the Serang District Court pointed out, the Constitutional Court's decision related to whether a particular bank was a state-owned enterprise, not whether that bank's property or resources were state ‘finances’.

Even though Expert 1's evidence was rejected, it raises no questions about his objectivity. In the Supreme Court decision he mentioned—a corruption case involving Frederick ST Siahaan (Finance Director of Pertamina, a state-owned oil and natural gas company) as defendant—the Supreme Court did, as Expert 1 observed, decide that the finances of a subsidiary of a state-owned enterprise were not state finances, citing the Constitutional Court decision. ⁹³ According to the facts agreed by the Supreme Court, on the direction of Pertamina Managing Director Karen Agustiawan, Siahaan signed an agreement for the USD 30 million purchase by PT Pertamina Hulu Energi (PHE) (a subsidiary of Pertamina) of a 10% participating interest in Manta Gummy Block (Australia), with Pertamina as a guarantor. When the Block was not as productive as anticipated, causing loss of around Rp 570 billion, both Siahaan and Agustiawan were convicted of corruption. But the Supreme Court acquitted them. ⁹⁴ In both cases, the Supreme Court held, inter alia, that PHE's finances were not state finances, because PHE was only a subsidiary of a state-owned enterprise, not a state-owned enterprise itself. ⁹⁵ The Serang District Court took a different but equally legally-defensible view, holding that an entity can have control over and responsibility for state finances even though it is not a state-owned enterprise. Such an entity (and its officers) can, therefore, be held to account for those losses. ⁹⁶

In the second case, the Central Jakarta District Court disagreed with Expert 2. The defendant had procured school equipment using prices from a list provided by an acquaintance (who he had already nominated to supply the goods) without regard to market prices. ⁹⁷ Prosecutors argued that this caused loss—the difference between the amount paid and the market price. ⁹⁸ A central issue in this case—also controversial in Indonesian legal circles and raised in cases discussed above—was whether a violation of administrative guidelines, an administrative error, or ‘lack of care’ could be an ‘unlawful act’ and form the basis of a corruption conviction if it results in financial loss to the state.

Expert 2 was called by the defence. The decision contains a summary of her testimony, presented in dot points. One point was ‘If there is no intent to break the law, an act of a government official has lacked care (kelalaian)’. ⁹⁹ We found nothing in her reported evidence about whether an administrative error could be an unlawful act for the purposes of corruption. However, the court found that, in her explanation, she had observed that ‘the error of the defendant, in the procurement of goods/services was an administrative mistake and not an illegal act’. ¹⁰⁰ The court then disagreed with this view, declaring that:

the defendant had, when performing his duties, violated [a presidential regulation] on procurement of goods/services using the state/regional budget, which caused loss to the state...[Even] the smallest of state losses must be accounted for, so the defence of the defence lawyers must be rejected. ¹⁰¹

On our reading, the court may have misconstrued Expert 2's testimony, who referred only to intent and lack of care, not administrative mistakes. It is also possible that her testimony was improperly recorded. Also possible is that the defence team misconstrued her testimony during closing arguments (which are not included in the transcript) and the judges simply responded to that without correcting it. Regardless, the court was not, in its published reasons, entirely transparent about Expert 2's testimony and how it handled that evidence. The court also did not address the main suggestion of Expert 2's testimony on this point—that defendants should not be convicted for acts that are fundamentally not criminal.

The court also disagreed with Expert 2 about which state bodies had authority to calculate loss to state finances in corruption cases. Again, this is a controversial legal issue in Indonesia, with some taking the view that only the national Audit Board (Badan Pemeriksa Keuangan, or BPK) has this authority. ¹⁰² The question here was whether an audit, which was performed by another government body—the Financial and Development Oversight Agency (Badan Pengawasan Keuangan dan Pembangunan or BPKP), could validly establish state loss that could ground a conviction. According to the court's summary, Expert 2 testified that while the BPK had authority, ‘there was also a Supreme Court Practice Note that explained that in addition to the BPK, there is also the BPKP’. ¹⁰³ On our reading, her testimony implied that either or both the BPK and the BPKP could calculate state loss for the purposes of corruption trials.

Again, this appears to have been misconstrued by the court or the defence. The court said that:

The defence quoted the opinion of [Expert 2] that only the BPK had authority to calculate state loss (Law 15 of 2005). [Accordingly, because] in this case state loss was calculated by the BPKP, the [calculation] cannot be used as evidence of state loss. ¹⁰⁴

The court then disagreed with the view that BPKP could not formally establish state loss, deciding that the prosecution's experts, supported by other evidence, ‘had convinced it that the BPKP's calculation was a legal fact that had convinced it that state loss had occurred’. ¹⁰⁵ Ultimately, prosecutors did not need to obtain evidence of loss from the BKP; the BPKP's calculation of state loss could support a conviction.

Part III: Explaining the use of expert evidence in Indonesia

The cases discussed in Part II demonstrate that many of the assumptions about expert evidence outlined in Part I do not bear out in practice. In very few of our cases did legal experts provide information about complex or new areas of law (the main justification put forward for expert legal evidence in Indonesia). In almost all cases, the evidence they provided was so rudimentary that all judges (and lawyers)—even those of doubtful competence (another justification)—must certainly have already known it. In our view, use of experts is not, therefore, necessarily an indicator of judicial incompetence or laziness. To be sure, some cases—particularly those where judges engaged with the expert evidence (sometimes even misconstruing it) to reject it—involved more complicated and contested legal issues. But the judges in those cases demonstrated an at least defensible understanding of the relevant legal issues.

There is also very little to indicate that parties use experts to successfully sway judges. The legal reasoning in most of our cases did not refer to expert evidence summarised or reproduced earlier in the decision. And, while experts have suggested how the law should be applied in cases at hand, judges did not follow those suggestions, at least expressly. Concerns about expert evidence usurping the judicial function have not, therefore, materialised. We also found no trend of judges favouring a particular expert's views, either expressly or by outcome. The pre-eminence of the expert and the number of experts parties call appear to have no effect. These findings beg the question: why do parties continue to call experts (preferably more than their opponents)?

The answer, in many cases, appears to lie in quirks of Indonesian evidence law and criminal process. As mentioned, the expert evidence discussed in Part II is usually reproduced in the decision itself, but it can take different forms. In some cases, the evidence appears to be a summary of oral testimony produced by a registrar (panitera). In others, the evidence is more formally structured, resembling a report. This may be a verbatim record of what the witness said during proceedings under oath, ¹⁰⁶ which the witness may have read from a pre-prepared statement. ¹⁰⁷ If the witness does not attend, someone else might read out the statement. This is often the party who called the witness, ¹⁰⁸ but is sometimes another participant whose name and position are not clearly specified in the transcript, if at all. ¹⁰⁹

Importantly, these report-like statements are often initially produced not for the trial, but rather at the request of police during their early investigations into the defendant and their alleged criminal act. ¹¹⁰ Since most police are not legal experts, they will often invite an expert to explain, in written form, the basic elements of any relevant offence, and whether on the collected evidence there is any prospect of conviction at trial. ¹¹¹ The KUHAP permits this. Article 120(1) states that ‘If investigators deem necessary, they can seek the opinion of an expert or a person who has special expertise’. This is to be given under an oath made before investigators indicating that the expert will provide the ‘best possible explanation…unless [prevented by] honour or dignity, or employment or office that requires maintaining confidentiality, in which case [he or she] can refuse to give the statement’ (Article 120(2)). Police will then ordinarily include such statements in the brief of evidence they pass on to prosecutors who, if they decide to proceed to trial, will include them in the brief they submit to court. In our view, this explains why expert evidence about basic legal concepts often appears in many published judicial decisions. The problem is that the statements tend to be based on preliminary evidence not yet tested at trial. We return to this issue below.

More sinisterly, however, police may consult an expert to produce a statement or report to bolster the weight of evidence they have against a suspect, to enable them to arrest and detain that suspect. Police can only arrest and detain if they have at least two pieces of ‘valid’ evidence. These are limited categories or types of evidence acceptable to prove guilt. They include documents (including electronic documents), electronic information (including digital and sound recordings), lay witness explanations, admissions, petunjuk (literally, ‘clue’, but often translated as ‘circumstantial evidence’) and expert explanations. ¹¹² If police have only one type of evidence against a suspect, they cannot legally pursue that suspect. Some lawyers have told us that to overcome this barrier, police can (and do) simply engage a legal expert to provide a statement. This statement then becomes the second piece of evidence that police need to proceed.

Unfortunately, this is tantamount to evidence manufacturing, as the following common scenario demonstrates. Police wish to arrest a suspect for an alleged crime but have only one lay witness to that crime. They simply engage an expert to make a statement indicating that the lay witness has described an act that meets the elements of that crime. This gives police two pieces of evidence—enabling them to arrest or detain the suspect—even though the expert has provided no evidence about whether a crime actually took place.

Also at play here is genuine uncertainty about whether a written expert statement produced before trial for police is admissible at trial, particularly if the expert who made it does not attend the trial for examination about its contents. ¹¹³ Part of the controversy concerns whether the statement can be classified as a ‘document’ (hence admissible as one under Article 184) or merely an ‘expert explanation’. Article 187 exhaustively defines ‘documents’. Included in the definition is a written statement from an expert that contains an opinion based on his or her expertise about a thing or a situation, as formally requested from them (Article 187(c)). To be admissible, these statements must be made under ‘oath of office’ or ‘supported by oath’.

As for ‘expert explanations’, Article 186 says that these are ‘what an expert declares in court’. However, this definition is muddied by the Elucidation to Article 186 itself, which states that expert explanations can also be given at the police and prosecutorial examination stages. These explanations are to be contained in a report ‘remembering the oath taken when receiving the office or employment’. (What this statement means is not entirely clear, but it appears to bind experts to any professional code of ethics they may have sworn to uphold when becoming a member of their respective professions, rather than referring to any oath that might be taken at the time the expert made the statement.) On our reading, if an expert report is not provided at the time of police examination, then the expert should attend trial to give his or her explanation, under an oath made before a judge. However, if that expert made a statement to police, then attendance at trial does not usually appear to be required, and the report containing the statement appears to be admissible, even if not made under oath or affirmation before police or the court.

A written expert report can, therefore, be formally classified as a ‘document’, an ‘expert explanation’ or both. Judges tend not to disclose the category into which expert evidence falls in any given case. Harahap, who calls this ‘dualism of evidence’, says that the way expert explanations are categorised is up to the judge, but that it does not matter because both are valid evidence with the same evidentiary weight. Either or both can be discounted if the judge decides to attach little weight to them (Harahap, 2000: 283). Theoretically, then, judges could, for example, give little evidentiary weight to an unsworn pre-trial witness statement. However, in practice, in some of our cases, police-sought expert explanations reproduced in the judgment did not disclose whether the statement was sworn or who it was made before. ¹¹⁴ This makes it difficult for judges to precisely determine the weight to accord to an expert explanation that is not in-court testimony. Indonesian judges can simply accord precisely the same weight to a pre-trial expert statement as testimony given in court.

Of course, many Indonesian lawyers say that expert witnesses should appear at trial to answer questions about the contents of their statements, even if they are not strictly required to. But Indonesian courts do not draw inferences about the dependability of evidence given by experts who do not appear. And the expert's attendance may add little to what they have provided in their written statement in any event. This is because experts who attend are usually simply asked to read out their statements. They are rarely effectively challenged on their evidence in Indonesian proceedings. To be sure, the parties and judges can and do ask questions of witnesses, but their testimony is not scrutinised, even dissected, as happens during cross-examination in other countries.

An example of this lack of scrutiny can be seen in a corruption case involving alleged money laundering in which Expert 3 appeared as a witness. ¹¹⁵ His testimony appeared to be intended to establish that a predicate crime did not need to be formally established before a court could consider whether the proceeds of that crime had been laundered. The transcript of his evidence given during the trial reveals that he was asked whether he knew of a previous Indonesian Supreme Court case, ¹¹⁶ two United States cases, ¹¹⁷ and an English case. ¹¹⁸ The reason for asking him about these cases was not disclosed in the case file; we presume they were put to him because they contradicted his view about predicate crimes. He admitted to having not read them—even the quite famous Supreme Court case. The transcript does not reveal who put these questions to Expert 3, but it appears that the questioner did not then pursue the obvious line of enquiry to challenge the correctness of Expert 3's evidence, or his expertise, as one might expect in an adequately-constructed cross-examination.

For unclear reasons, Expert 3 then supported his conclusion by explaining that other countries also did not require proof of a predicate offence. However, the basis for this explanation about foreign law was not convincing. Rather than pointing to relatively authoritative sources, such as legal instruments, judicial decisions or commentaries, he instead mentioned conversations about predicate offences he had with foreigners at various fora. For example, he mentioned that at a ‘discussion in Bangkok with Indonesian judges on 9 April 2013’, Dutch Supreme Court Judge Mr Buruma and an American judge, ‘Mrs Virginia’, said that money laundering did not require that a predicate offence be proved. The expert claimed that the same points were made by the Dutch Advocate General Mr Nico Kijzer at Hotel Meridian in Jakarta on 20 May 2013, after Expert 3 had asked him about predicate offences, and in discussions between anti-corruption court judges, the Anti-corruption Commission, Australian county court judge Michael McInerney and senior lawyer Mrs Sylvia Grono on 27 November 2013 in Jakarta. ¹¹⁹ Again, he did not appear to be pushed on whether these sources were appropriate or authoritative.

We make one final observation here. During our research, we encountered examples of blatantly inconsistent evidence about the same legal issue being given by some experts in different trials. None of these examples involved any of our three experts. In one case, for example, a legal expert testified that a statement from the National Police Forensic Laboratory could be classified as an expert statement under Indonesian evidence law. ¹²⁰ However, several years later, in another case, the same expert reached the opposite conclusion. ¹²¹ To our knowledge, the expert faced no cross-examination in the latter case about the inconsistency.

Conclusion

Using expert explanations from legal academics in trials is now an entrenched practice in Indonesia in many types of case, if not all types. As we have shown, in criminal trials, legal experts—sometimes multiple experts—provide explanations about the content of the criminal law (and sometimes even its application to the case at hand). There is no express legal prohibition on this (even though it sits uncomfortably alongside ius curia novit and the essence of the judicial function—to identify and apply the relevant law). Yet our cases cast doubt on the utility of legal expert evidence, at least for judicial decision-making. Judges appear reluctant to cite that evidence, let alone openly interrogate it. There is little to suggest that judges are influenced by it, at least overtly, even if provided by a well-respected expert. The lack of apparent influence is not surprising. After all, in our cases, experts rarely gave evidence about legal concepts or bodies of law (and their application) that judges do not already know.

If judges pay expert explanations no heed, then what is the point of allowing them? We suggest that the answer to the question lies less in transcripts of proceedings and judicial decisions (upon which this research was based), and more in the briefs of evidence that police collect, prosecutors refine and courts consider when hearing trials and making decisions. Police the world over may, quite appropriately, consult experts—for example, to help them determine whether they have collected sufficient evidence to proceed against a suspect. However, as discussed, in Indonesia, the expert usually prepares a written report that then itself becomes a further piece of valid evidence, even though it adds nothing to the weight of evidence against a suspect or defendant. Because police pay these experts—and sometimes use the same experts repeatedly—one can expect that these experts will almost inevitably opine that the evidence, however slim, indicates that a crime has occurred and that the suspect police have identified perpetrated it. Critically, the expert will probably have no contrary evidence (from the defence, for example) to consider when producing this statement, yet the statement can have full evidentiary weight—equivalent to that of uncontested witness testimony given in court. As mentioned, this is police-manufactured evidence and is unfair to defendants.

Even though, as we have shown, judges rarely appear to rely on expert evidence, allowing it creates an air of judicial incompetence, thus further undermining public confidence in the Indonesian judiciary. As one of the few Indonesian critics of judicial reliance on experts has written in the context of the Constitutional Court:

The existence of experts in legal studies in Constitutional Court decisions is strange because, indirectly,…this is tantamount to questioning the expertise of constitutional court judges in their command of the law, particularly in relation to the Constitution and matters of state (Bisariyadi, 2020: 742).

However, the status quo is likely to prevail for some time, primarily because using experts is still perceived to be beneficial for all parties—police, prosecutors, judges and parties—including in criminal cases. Police, prosecutors and defence lawyers can use expert statements to strengthen their cases (or at least to make them appear stronger than they are). And, even where judges do or should know the law relevant to cases over which they preside, hearing directly from an expert is still probably easier than consulting legal textbooks.

Importantly, legal academics—whatever their speciality—have no incentive to criticise these practices. Many high-profile academics who would ordinarily be vocal critics about unfairness or impropriety in the legal system appear as legal expert witnesses themselves, to supplement meagre university salaries (Dzulfikar, 2022). They are exposed to few reputational risks for doing so. In the absence of rigorous cross-examination, legal experts can largely can ‘get away’ with providing evidence that favours the party that pays them, even if this involves stretching the legal arguments they make.