Criminal careers have been extensively researched and many studies have been carried out to test the numerous theories surrounding the subject. However, there are several problems associated with the past research. This next section discusses the main problems identified that directly affect the areas that this study examines.
As previously mentioned above, there are many studies that have used broad categories of offences when looking at patterns of offending over time (Baker et al., 2013, Bartolucci et al., 2007, Moffitt et al., 1996, Piquero et al., 1999). These studies can miss changes in offending types over time and misinterpret specialisation in offending. This is because an offender may commit a different type of offence from one offence to the next, but both the offences come under the same category of offences. Therefore, in the results it appears that the offender is committing the same offences sequentially and will be considered specialised. For example, the studies that have used two broad categories (violent vs non-violent) (Brame et al., 2004, Lynam et al., 2004, Osgood and Schreck, 2007) may consider a person who has committed robbery and then murder as specialised, as both the offences fall under violent category of offending. Being able to separate these offences is important for analysis as noticing these changes in offending is key to understanding the crime mix patterns that occur within the data. As the majority of crimes committed tend to be non-violent offences, these studies that have primarily focused on more serious crime types and violent offences to examine specialisation, have ignored the majority
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In this thesis, a wide range of different offence categories are included in the analyses, therefore identifying crime mix patterns in the conviction datasets being modelled will be more thorough and accurate.
When analysing specialisation in offending, many early studies have used modelling approaches which look at offences committed sequentially such as the Forward Specialisation Coefficient (FSC) (Farrington et al., 1988, Kempf, 1987, Paternoster et al., 1998). The FSC measures the tendency to repeat an offence in succession on a scale from 0 to 1 (See Farrington et al., 1988). An offender is considered specialised, as they always commit the same offence type over and over. However, an offender is also specialised if they commit the same type of offences within a domain of
offending. The FSC however, wouldn’t consider an offender to be specialised if they for example, they commit burglary then theft then burglary again. This is because they haven’t committed the same offence in succession.Another issue with sequential analysis is that it requires data which is date-ordered, which can be a problem with self-report data. Choosing an appropriate methodology to examine crime mix patterns and to provide evidence of specialisation or versatility in offending needs careful consideration.
Many previous studies have only covered criminal careers of young offenders (Glueck and Glueck, 1930, Farrington and West, 1990, Loeber and Snyder, 1990, Tracy, 1990, Wolfgang et al., 1972). This neglects to capture the offending behaviour into adulthood, therefore less is known about the offending behaviour of older
offenders. It also fails to catch offenders who are late starters or falsely assumes offenders may have desisted as they may restart offending at a later age due to changes in life circumstances (Andersson et al., 2012). Moreover, the research and knowledge on highly chronic adult offenders is scarce due to them occupying only a
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small proportion of offending samples (Tarling, 1993). However, it is of great importance to be able to identify and understanding the offending behaviours of chronic adult offenders.
Along with the lack of studies into adult offending patterns, is also the shortage of research into the offending patterns on female offenders. Most criminal career theories and investigations are based upon research of male offenders (Blokland, 2005). This neglects the discovery of different patterns of criminal offending that could be displayed by female offenders. Certain researchers have suggested that females criminal career trajectories differ to those of male offenders (Silverthorn and Frick, 1999). Studies by Block et al. (2010), Blokland et al. (2010), and Francis et al. (2010) have all investigated female offending and contributed the knowledge on female criminal careers. However, there is still a need to study female offending as gaining precise knowledge on the criminal behaviour is important for criminology theories and for criminal justice practitioners (Block et al. 2010). This is because certain interventions aimed at crime reduction may be ineffective on female offenders due to them being based on male offending patterns.
Finally, it is worth mentioning the issue with identifying ‘chronic’ offenders, as defining what constitutes a chronic offender is particularly difficult. Chronic offenders
according to Blumstein et al (1986) were offenders who committed a high number of serious crimes over a prolonged time period. Studies such as Wolfgang et al. (1972) consider an offender to be chronic if they commit 5 or more offences or contact with the police. However other researchers believe an offender that commits 10 or more offences is considered chronic (Chaiken and Chaiken, 1982, Ezell and Cohen, 2005, Horney and Marshall, 1991). Deciding upon how many offences to be the cut off between a chronic and non-chronic offender is not straight forward. For example defining that an individual with 5 or more offences or instead 8 or more is chronic, will create two entirely different groups with varying numbers of how many of the
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population are chronic offenders (Skardhamar, 2009). Although identifying and separating the chronic offenders is important and helpful it still does not tell us that much about the offending behaviours of these particular offenders. Knowing what sort of offences and the patterns and paths they follow is ultimately just as important and will provide a much better understanding of why these offenders commit more offences.