FBI researched personalities, behaviours, family backgrounds, crimea and motives of serial killers. Using information and their experience, developed a classification system (organised and disorganised) for several idfferent crimes including murder and ****. Each 'type' of crime displays a different set of characteristics.
Very limited as only applies to crimes which leave significant evidence and are multiple offenses. Sample origninally used by FBI was neither large nor random. FBI interviewed 36 convicted serial murders from an opportunity sample - interviews not standardised resulting in classification system based on those who had been caught who may differ from those in important ways who are still at large.
Profiling far from guarentees a conviction. However, Douglas (1981) reviewed cost and benifits for profiling for FBI - findings show that even though it rarely led directly to offender (15/192 cases) but 77% of cases it helped to focus the investigation. Positive outlook for US profiling system as shows that helps find criminals.
However, too simplistic. Canter (2004) used SSA evidence from 100 US murderers and found 'power/control' killings were found in over half of the sample and therefore typical of most muderers. Shows organised'disorgannised classification system not reliable as some characteristics may be similar in both categories.
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British and geographical
British - assumes individuals are consistant in their personalities. Interpersonal coherense suggests that evidence about the offenders behaviour at the crime scene will reflect the way they act in day-to-day life. E.g. House (1997) different types of **** could be identified by the characteristics from the crime scene. Shows that precautions offender takes to avoid detection can be useful - Davis et al (1997) rapists who attempted to conceal fingerprints likely to be convicted for burglary.
May not be useful. Copson (1995) used questionnaires and police officers to see whether forensic profiling is useful. More than half said it provided something extra tot he case and 80% said the information was useful. Only 14% said it assisted in solving a case and 3% said it resulted in the identification of the offender. Showes that profiling offer reassurance that an investigation on trachk. However, profilings intention is to help capture criminals so study shows that UK apporach is not valid as it doesnt do what it is supposed to be.
Geographical - analyses locations of series of crimes to indicate where offender might live, work, socialise or travel - used for serial muder or **** cases or arsona dn robbery.
Useful - Canter and Larkin (1993) tested models of offender movement using data from 45 **** cases and found a pattern that showed 87% of rapists moved in a region around their homes. However small sample. Snook et al (2005) 63% of serial muderers kill less that 10KM from homes. Goodwill and Alison (2006) geographical most useful and behaviourla data least helpful.
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