NCJ Number
229343
Journal
Journal of Quantitative Criminology Volume: 25 Issue: 4 Dated: December 2009 Pages: 419-441
Date Published
December 2009
Length
23 pages
Annotation
Since it has not yet been determined whether newly developed research methods applied to offending specialization are studying the same operational definition of "specialization," this study used four frequently applied approaches to this issue with a single dataset.
Abstract
The authors believe that their general description of "offending specialization" as "a tendency to repeat the same crime or type of crime over time" is a fair representation of the concept, based upon theory and previous research. Given this definition, all of the methods used in this study revealed that some degree of offending specialization was present in the data, and all four methods reached similar core findings, which is promising for knowledge building. None of the methods found that distinctions among offender types in terms of their criminal behavior were significantly strong. Because offenders rarely have crime profiles that span every possible offense type or involve only one offense type, researchers must often decide tipping points for classifying offenders as "generalists" and "specialists." The four methods used were the forward specialization coefficient, the diversity index, latent class analysis (LCA), and a multilevel latent variable (IRT) approach. These four methods provide a fair cross-section of the various methods used to detect and describe offender specialization. The IRT model is apparently the most comprehensive; it incorporates all offenses that occur in a single event; includes all offenders, not only those who commit at least two offenses; and includes the frequency of all offenses. It also provides for specific hypothesis tests regarding the degree of specialization and the impact of relevant covariates. The study sample consisted of 1,308 juvenile inmates in 3 California Youth Authority facilities during the 1960s. The sample is considered representative of the population of juvenile offenders incarcerated in California during this time period. 6 tables, 72 references, and appended supplementary data