Much of the knowledge base on offense specialization indicates that, although there is some (short-term) specialization, it exists amidst much versatility in offending. Yet this general conclusion is drawn on studies using very different conceptualizations of specialization and emerges with data primarily through the first two to three decades of life. Using data on a sample of Dutch offenders through age 72 years, this article introduces and applies a new method for studying individual offender specialization over the life course. The results indicate that although, in general, individual offending patterns over the life course are diverse, there is also evidence of an age—diversity curve. Linking offense frequency trajectories to the estimated diversity index, the authors also examine distinct specialization patterns across unique trajectory groups. Implications for theory and research are outlined.
Agresti, A., & Agresti, B.F. ( 1978). Statistical analysis of qualitative variation . Sociological Methodology, 9, 204-237.
2.
Armstrong, T.A. ( 2008a). Exploring the impact of changes in group composition on trends in specialization. Crime & Delinquency, 54, 366-389.
3.
Armstrong, T.A. ( 2008b). Are trends in specialization across arrests explained by changes in specialization occurring with age? Justice Quarterly , 25, 201-222.
4.
Armstrong, T.A., & Britt, C.L. ( 2004). The effect of offender characteristics on offense specialization and escalation. Justice Quarterly, 21, 843-876.
5.
Blokland, A.A.J. ( 2005). Crime over the life span: Trajectories of criminal behavior in Dutch offenders. Leiden: Netherlands Institute for the Study of Crime and Law Enforcement.
6.
Blokland, A.A.J., Nagin, D.S., & Nieuwbeerta, P. (2005). Life span offending trajectories of a Dutch conviction cohort. Criminology, 43, 919-954.
7.
Blokland, A.A.J., & Nieuwbeerta, P. (2005). The effects of life circumstances on longitudinal trajectories of offending. Criminology, 43, 1203-1240.
8.
Blumstein, A., Cohen, J., Das, S., & Moitra, S.D. ( 1988). Specialization and seriousness during adult criminal careers. Journal of Quantitative Criminology, 4, 303-345.
9.
Blumstein, A., Cohen, J., Roth, J. A., & Visher, C. A., (Eds.). (1986). Criminal careers and "career criminals."Washington, DC : National Academies Press.
10.
Britt, C.L. ( 1996). The measurement of specialization and escalation in the criminal career: An alternative modeling strategy. Journal of Quantitative Criminology, 12, 193-222.
11.
Bushway, S., Sweeten, G., & Nieuwbeerta, P. (2009). Measuring long term individual trajectories of offending using multiple methods. Journal of Quantitative Criminology, 25, 259-286.
12.
Farrington, D.P. ( 1986). Age and crime. In M. Tonry & N. Morris (Eds.), Crime and justice: An annual review of research (Vol. 7, pp. 189-250). Chicago, IL: University of Chicago Press.
13.
Farrington, D.P. ( 2003). Developmental and life-course criminology: Key theoretical and empirical issues-the 2002 Sutherland Award Address. Criminology , 41, 221-255.
Fox, J. ( 2002). Nonparametric regression: Appendix to: John Fox, An R and S-Plus companion to applied regression. Retrieved from http://cran.r-project.org/doc/contrib/Fox-Companion/appendix.html
17.
Gottfredson, M.R., & Hirschi, T. ( 1990). A general theory of crime. Stanford, CA: Stanford University Press.
18.
Jones, B.L., Nagin, D.S., & Roeder, K. ( 2001). A SAS procedure based on mixture models for estimating developmental trajectories. Sociological Methods & Research , 29, 374-393.
19.
Kurlycheck, M.C., Brame, R., & Bushway, S.D. ( 2006). Scarlet letters and recidivism: Does an old criminal record predict future offending? Criminology and Public Policy , 5, 483-504.
20.
Kurlycheck, M.C., Brame, R., & Bushway, S.D. ( 2007). Enduring risk? Old criminal records and short-term predictions of criminal involvement. Crime & Delinquency , 53, 64-83.
21.
Lynam, D.R., Moffitt, T.E., & Piquero, A.R. ( 2004). Specialization and the propensity to violence: Support from self-reports but not official records. Journal of Contemporary Criminal Justice, 20, 215-228.
22.
Mazerolle, P., Brame, R., Paternoster, R., Piquero, A., & Dean, C.W. ( 2000). Onset age and offending versatility: Comparisons across gender. Criminology, 38, 1143-1172.
23.
McGloin, J.M., Sullivan, C., Pratt, T.C., & Piquero, A.R. ( 2007). Local life circumstances and offending specialization/versatility: Comparing opportunity and propensity models. Journal of Research in Crime and Delinquency, 44, 321-346.
24.
Moffitt, T.E. ( 1993). "Life-course-persistent" and "adolescence-limited" antisocial behavior: A developmental taxonomy. Psychological Review, 100, 674-701.
25.
Moffitt, T.E. ( 1994). Natural histories of delinquency. In G. M. Weitekamp & H.- J. Kerner (Eds.), Cross-national longitudinal research on human development and criminal behavior (pp. 3-64). Dordrecht, Netherlands: Kluwer Academic.
26.
Monahan, K., & Piquero, A.R. ( 2009). Investigating the longitudinal relation between offending frequency and offending variety. Criminal Justice and Behavior , 36, 653-673.
27.
Nagin, D.S. ( 2005). Group-based modeling of development. Cambridge, MA: Harvard University Press .
28.
Nagin, D.S., & Land, K.C. ( 1993). Age, criminal careers, and population heterogeneity: Specification and estimation of a nonparametric, mixed Poisson model. Criminology, 31, 327-362.
29.
Nieuwbeerta, P., & Blokland, A.A.J. (2003). Criminal careers of adult Dutch offenders (Codebook and documentation). Leiden: Netherlands Institute for the Study of Crime and Law Enforcement .
30.
Osgood, D.W., & Schreck, C. ( 2007). A new method for studying the extent, stability, and predictors of individual specialization in violence. Criminology , 45, 273-312.
31.
Paternoster, R., Brame, R., Piquero, A., Mazerolle, P., & Dean, C.W. ( 1998). The forward specialization coefficient: Distributional properties and subgroup differences. Journal of Quantitative Criminology, 14, 133-154.
32.
Paternoster, R., Dean, C., Piquero, A., Mazerolle, P., & Brame, R. ( 1997). Generality, continuity and change in offending careers . Journal of Quantitative Criminology13, 231-266.
33.
Piquero, A.R. ( 2000). Frequency, specialization, and violence in offending careers. Journal of Research in Crime and Delinquency, 37, 392-418.
34.
Piquero, A.R. ( 2008). Taking stock of developmental trajectories of criminal activity over the life course. In A. Liberman (Ed.), The long view of crime: A synthesis of longitudinal research (pp. 23-78). New York, NY: Springer .
35.
Piquero, A.R., Blumstein, A., Brame, R., Haapanen, R., Mulvey, E.P., & Nagin, D.S. ( 2001). Assessing the impact of exposure time and incapacitation on longitudinal trajectories of criminal offending. Journal of Adolescent Research, 16, 54-74.
36.
Piquero, A.R., Farrington, D.P., & Blumstein, A. ( 2003). The criminal career paradigm. In M. Tonry (Ed.), Crime and justice: A review of research (Vol. 30, pp. 359-506). Chicago, IL: University of Chicago Press.
37.
Piquero, A.R., Paternoster, R., Mazerolle, P., Brame, R., & Dean, C.W. ( 1999). Onset age and offense specialization. Journal of Research in Crime and Delinquency, 36, 275-299.
38.
Sampson, R.J., & Laub, J.H. ( 1993). Crime in the making: Pathways and turning points through life. Cambridge, MA.: Harvard University Press.
39.
Sampson, R.J., & Laub, J.H. ( 1997). A life-course theory of cumulative disadvantage and the stability of delinquency. In T. Thornberry (Ed.), Advances in criminological theory: Vol. 7. Developmental theories of crime and delinquency (pp. 133-161). New Brunswick, NJ: Transaction.
40.
Spelman, W. ( 1994). Criminal incapacitation. New York, NY: Plenum.
41.
Sullivan, C.J., McGloin, J.M., Caudy, M., & Ray, J. ( 2009). Detecting specialization in offending: Comparing analytic approaches. Journal of Quantitative Criminology, 25, 419-441.
42.
Sullivan, C.J., McGloin, J.M., Pratt, T.C., & Piquero, A.R. ( 2006). Rethinking the "norm" of offender generality: Investigating specialization in the short-term. Criminology , 44, 205-240.
43.
Teknomo, K. ( 2007). Kernel Regression. Retrieved from http://people.revoledu.com/kardi/tutorial/regression/kernelregression/
44.
Tracy, P.E., & Kempf-Leonard, K. (1996). Continuity and discontinuity in criminal careers. New York, NY: Plenum.
45.
Tracy, P.E., Wolfgang, M.E., & Figlio, R.M. ( 1990). Delinquency careers in two birth cohorts. New York, NY: Plenum.
46.
Wolfgang, M.E., Figlio, R.M., & Sellin, T. ( 1972). Delinquency in a birth cohort. Chicago, IL: University of Chicago Press.
