Despite some questions from theorists and empirical researchers, the categorization of offenders nonetheless retains some appeal, particularly among policymakers, practitioners, and the general public (see Lieb, Quinsey, & Berliner, 1998; Matson & Lieb, 1997). Differential incarceration and treatment plans, for instance, often assume some offender types, whether in terms of specific groups like sex offenders or the general consideration of violent/ nonviolent behavior. Legislation directed against particular subgroups of offenders may be enacted when public outcry regarding a well-known case is high. Simon (1997) points out that few outside the research community understand that offender specialization is a relatively rare occurrence. Consequently, an understanding of the degree to which offenders specialize can inform debates about key aspects of justice processing and crime prevention (Blumstein et al., 1986). For example, specific sanctions and treatment for drug offenders may be more palatable (and effective) if it can be demonstrated that such offenders tend not to engage in other offenses that pose a greater threat to public safety.
Clearly, attaching generalized labels to offenders offers practitioners and policymakers an opportunity to simplify decision making because officials can develop a template for dealing with a particular group and then apply that approach to those who fall in that classification. At the same time, in practice, the viability of this perspective does in part hinge on the reality of whether or not such types, or at least concentrated behavioral patterns, truly exist. Thus, this becomes an important information point in balancing the cost and benefit of particular forms of justice response to such offenders. Although there are others (e.g., domestic violence offenders) (Simon, 1997), two groups that have been a specific focus of policy-related discussion of specialization are drug offenders and sex offenders.
A. Drug Offenders
The question of sentencing for low-level drug offenders has been a matter of some debate. Very little empirical literature has examined this question in relation to its specialization assumption, however. DeLisi (2003) addresses the argument of some who contend that there is a group of “drug offenders” who are generally nonviolent and do not pose much of a threat to public safety as they are only users. The held belief is that imprisoning these individuals represents an overly harsh and wasteful reaction on the part of society. DeLisi examined the criminal arrest histories of 500 detained offenders to assess whether their offending careers reflect specialization in drug offenses or generalized criminal behavior. He found that drug offenders, characterized as having a history of imprisonment for drug use/possession, tend to engage in a variety of offenses over their careers and were actually more likely than nondrug offenders to engage in violent, property, and nuisance offenses. Based on these findings, DeLisi casts doubt on the contention that drug offenders are specialized and therefore should be treated with leniency because they pose little risk to society. Unfortunately, work in this area is quite limited, so it is important that the issue is studied further in the context of specialization. Still, the issue of response to drug offenders provides one example of the important policy discussions inherent in the study of specialization and versatility in criminal behavior.
B. Sex Offenders
Due in large part to its policy implications, specialization among sex offenders has received a great deal of attention (e.g., Lussier, 2005; Miethe et al., 2007; Simon, 1997). This comes at least in part because there has been a move toward specialized sanctions and treatment for sex offenders (Simon, 1997). For example, Megan’s Law provides for public notification regarding known sex offenders in the community, and civil commitment procedures permit authorities to house these offenders in secure, residential treatment facilities beyond the completion of their criminal sentence if they are still deemed to be a threat to the community. Both approaches imply some degree of specialization.
Specialization studies focused on sex offenders seek to better understand whether this particular group of offenders differs from others in ways that justify considering them as a distinct group for the purposes of treatment and sanctions. Studies by Lussier (2005) and Simon (1997) looked at this question specifically. Using the proliferation of measures aimed specifically at sex offenders as a pretext, Lussier undertook a comprehensive review of the literature related to specialized and generalized offending among that group. Based on studies that compare recidivism rates for sex offenders to those of nonsex offenders, he concluded that sexual crime does not engender greater levels of specialization than other crimes. Other studies did find, however, that there were differences in degree of specialization between offenders who victimized children compared to those whose offenses were perpetrated against adult women. Overall, Lussier reported mixed findings with regard to specialization and generality in offending but states that sex offenders do not appear to limit themselves strictly to that area of criminal behavior. Simon (1997) came to a similar conclusion in a review of the literature on domestic violence offenders, sex offenders, and general population criminals. In looking at sex offenders specifically, she indicates that findings of generality in criminal histories are often implicit even in studies that treat them as a distinct group.
Drawing on a similar premise as Lussier (2005), Miethe and colleagues (2007) examined the offending patterns of a large sample of sex offenders released from prison in the mid-1990s. They found that, in comparison to other offender groups, sex offenders exhibited lower probabilities of committing the same offense for adjacent arrests. Furthermore, they identified offending versatility regardless of whether they examined raw probabilities of repeated sex offenses, the forward specialization coefficient, or the diversity index. Thus, the sex offenders in this large, nationally representative sample did not appear to be “persistent specialists” as is often assumed. Studies of the type mentioned here further emphasize the importance of fully considering the available evidence regarding potential specialization of offending in determining whether policies aimed toward specific groups of offenders are likely to be successful.