II. Criminal Careers
To understand what crime over the life course actually means for research and practical purposes, it is important to become familiar with the criminal career terminology. In its most rudimentary form, a criminal career is the “characterization of the longitudinal sequence of crimes committed by an individual offender” (Blumstein, Cohen, Roth, & Visher, 1986, p. 12). As the word longitudinal implies, there is an inherent time dimension to criminal careers. Furthermore, this suggests that there are identifiable start and end points that allow researchers to chart out an individual’s criminal career length.
The criminal career paradigm acknowledges that certain individuals start their criminal activity at one particular age, continue to commit various crimes for some period of time, and then essentially quit offending. Considering this assumption, the criminal career framework suggests the need to examine causes and correlates related to why and when individuals start offending (onset), why and how they continue offending (persistence), why and whether offending becomes more frequent or serious (escalation) or specialized, and why and when people stop offending (desistance).
Although one of the earliest criminal career studies was the qualitative depiction of delinquency presented by Clifford Shaw (1930) in The Jack Roller, criminal career research soon turned noticeably quantitative. Sheldon Glueck and Eleanor Glueck’s pioneering work, 500 Criminal Careers (1930), and a follow-up study entitled Unraveling Juvenile Delinquency (1950) provided criminologists with the most definitive and detailed source on the correlates of crime and how crime fluctuated over the life course among 500 delinquent and 500 matched control youth growing up in Boston. Not only was the Gluecks’s study unique and rigorous in its methodological design, but also the data provided by the Gluecks were considerably comprehensive. For instance, the Gluecks collected a wealth of information from self-reports (participant, parent, and teacher interviews) and gathered data from official records (police, court, and corrections). Thus, the richness of these data was unprecedented in its time and served as one of the key sources for criminological theorizing for some time. It continues to inform criminological theory today.
Quite some time after the Gluecks’s pioneering efforts, Marvin Wolfgang and his colleagues successfully completed one of the most well-known studies to date of the longitudinal progression of crime over the life course. This research, referred to as the Philadelphia Birth Cohort Study (Wolfgang, Figlio, & Sellin, 1972), was a retrospective study of criminal activity among all 9,945 males born in the city of Philadelphia (with continual residence through age 17) in 1945. Although the study was limited in that it contained only basic demographic information and relied solely on official sources of data, two of its key findings were groundbreaking at the time. The first important finding was that nearly one third of the cohort had an official police contact by age 17, and most of these offenders were “one-timers” in that they did not accumulate another police contact after their initial offense. Second, and perhaps more important, Wolfgang et al. discovered that only 6% of the cohort and 18% of the cohort’s offenders were responsible for committing roughly half of all the offenses and about two thirds all of the violent offenses. In a 10-year follow-up study of 10%of the original Philadelphia birth cohort, Wolfgang, Thornberry, and Figlio (1987) found that these chronic offenders had increased the seriousness of their offending into adulthood. In an effort to replicate and extend these research findings, Tracy, Wolfgang, and Figlio (1990) conducted the Second Philadelphia Birth Cohort Study, which was a retrospective study of the official records of more than 27,000 individuals who were born in Philadelphia in 1958 and socialized in the 1960s and 1970s. Although the prevalence of offending in general was similar to that of the first Philadelphia Birth Cohort Study, Tracy et al. found even higher rates of chronic offending among the members of the Second Philadelphia Birth Cohort. More specifically, they found that the chronic offenders represented 7% of the cohort and 23% of the offenders yet were responsible for committing 61% of all the offenses, including 60% of the homicides, 75% of the forcible rapes, 73% of the robberies, and 65% of the aggravated assaults.
The novel and influential findings generated from both the Gluecks’s and Wolfgang et al.’s birth cohort studies stimulated a series of other well-recognized longitudinal studies that have made notable contributions to the criminological literature in recent years. With some exceptions, a number of these studies are relatively recent, and thus not enough time has passed to enable tracking of these individuals into middle/late adulthood. However, there are two such examples of efforts that have been undertaken to follow participants from childhood into middle/late adulthood. Laub and Sampson (2003) are credited with the first of these efforts, wherein they conducted a qualitative and quantitative analysis of a follow-up of the Gluecks’s (1930) study (reviewed earlier) of the criminal careers of the 500 Boston-area male delinquents through age 70. In comparison, Piquero, Farrington, and Blumstein (2007) most recently presented the results of a thorough analysis of the criminal careers of 411 South London males from age 10 to 40 who participated in the Cambridge Study in Delinquent Development (West & Farrington, 1973).
It is important to note that Laub and Sampson’s (2003) follow-up study of the Boston delinquents is the longest longitudinal study of criminal activity in the field. In recognition of this, a series of key findings from their research efforts are worth highlighting. Although the results from a trajectory analysis suggested that there were six groups of individuals who demonstrated unique patterns of involvement in crime over the life course, the trajectory groups for the most part appeared to desist in middle/late adulthood, with virtually no group demonstrating continued involvement in crime at age 70.Although further trajectory analysis results disaggregated by crime type (property, violent, alcohol/drugs) revealed interesting similarities and differences compared with the aggregate trajectory analysis such that property crime trajectories mirrored the aggregate trajectories, violent crime trajectories appeared to peak later, and alcohol/drug trajectories seemed relatively stable throughout young and early/middle adulthood, subsequent attempts to determine key risk/ protective factors that distinguished trajectory groups from one another were not fruitful.
Nevertheless, as mentioned earlier, Laub and Sampson (2003) also incorporated a qualitative element into their research in that they conducted extensive interviews with 52 of the delinquent males. On the basis of the individual interviews, it appeared that criminal justice intervention was a risk factor for some and a deterrent for others—in other words, some of the respondents reported that their criminal justice involvement caused them to stop their offending, whereas others indicated that their criminal justice involvement increased/enhanced their continued participation in offending. Another key finding from Laub and Sampson’s interviews of the Gluecks’s (1930) participants was in regard to life transitions. Their qualitative analysis appeared to suggest that marriage was a key source of informal social control, or a turning point, in their lives that caused them to give up their involvement in crime.
As a point of comparison, Piquero et al.’s (2007) research represents the second study that involves long-term follow-up of individuals tracked from childhood into middle/late adulthood. In their analysis, Piquero et al. used data from the Cambridge Study in Delinquent Development (West & Farrington, 1973) to investigate and describe the offending patterns of 411 South London males who were first contacted at the ages of 8 through 10 in the early 1960s for participation in the study. The findings that emerged from Piquero et al.’s efforts were based on the official conviction records of the males at age 40 along with a series of self-reports of their involvement in criminal activity in order to gather information related to the progression of their offending over time.
A series of key findings from Piquero et al.’s (2007) analysis relate to each of the respective dimensions of criminal career research and have import for life course criminology. The first of these results is in regard to the prevalence of offending, the peak age of criminal activity, and the stability/ variability of crime over the life course. Piquero et al. revealed that nearly 2 out of every 5 of the South London males (e.g., 40%) accumulated an official conviction for a crime at some point in their lives. However, it appeared that the prevalence of offending for the sample peaked in late adolescence, at approximately age 17. Furthermore, the results indicated that for the most part the frequency of offending tended to follow the prevalence (with violence being the exception) and that there was a considerable degree of stability in offending across age.
The next set of significant research findings germane to criminal career dimensions and life course criminology were onset and frequency and severity of offending, offense specialization, and career length. Regarding the relationship between onset age (the age at which an individual commits his or her first offense) and frequency of offending and severity of offending, Piquero et al. (2007) found that an early onset of offending was related to having a more extensive criminal career as determined by accumulating numerous convictions, having a higher probability of participation in violence, demonstrating a longer criminal career, and displaying involvement in many different types of offenses. Furthermore, there was virtually no evidence of specialization in violence among the offenders from South London. In contrast, the results seem to suggest that involvement in violence was related to offending frequency such that individuals who were committing the greatest number of offenses were also those who were the most likely to have a violence conviction. Thus, violent offenders just tend to roll the dice more often. Turning toward career length, Piquero et al.’s results suggested that the average length of a criminal’s career (measured as the time from first offense to the time at last offense) was 10 years and that there was a general decline in age for both residual career length and residual number of offenses.
The last two key findings from Piquero et al.’s (2007) analysis can be directly compared with the early criminal career research on chronic offenders and chronic offending (e.g., Wolfgang et al.’s [1972, 1987] studies) and Laub and Sampson’s (2003) trajectory analysis with the Gluecks’s (1930) data. Similar to the evidence described earlier in the discussion of Wolfgang et al.’s (1972, 1987) studies, Piquero et al.’s analysis of chronic offenders and chronic offending found that a small group of the males with five or more convictions was responsible for a significant amount of the sample’s total convictions. At the same time, their analysis also indicated that the probability of recidivism after the fourth conviction was very similar thereafter, that is, 84.5%. Finally, whereas Laub and Sampson’s trajectory analysis with the Gluecks’s data revealed six trajectory groups through age 70, Piquero et al.’s trajectory analysis of the conviction records among the South London males suggested the presence of five distinct groups of offenders. Despite this difference, like Laub and Sampson’s results, each of the trajectory groups identified in Piquero et al.’s analysis had unique shapes and levels of offending through age 40 and varied on several criminal career dimensions. In addition, Piquero et al. were also able to identify a set of environmental and individual risk factors that were able to distinguish membership in the five distinct trajectory groups.