AO3

• Canter et al tested validity of organised/disorganised distinction, used info from 100 serial killers in USA, each case assessed for presence of 36 characteristics identified and found a subset of organised characteristics was typical of most, and disorganised were much rarer and did not occur together often enough to be considered a type 
• There is no clear distinction between organised and disorganised offenders, but can argue that this gives some validity to the organised category - Godwin argues organised-disorganised is a continuum as most killers have multiple contrasting characteristics and don't fit into one 'type'
• Unsupportive evidence - Pinzzotto and Finkel compared 5 different groups on their ability to write profiles of a solved murder case and found that detectives without profiling experience were significantly more accurate than expert profilers and detectives with profiling evidence suggesting there is a lack of effectiveness and validity. A reason for this could be categorisation of offenders may lead to ignoring other characteristics or pieces of info that may be relevant
• Criticised for being developed from unreliable sample - 36 American killers too small and unrepresentative to construct a classification system. Interviews not a fully reliable source of information (some criminals may play-up their behaviour in order to gain notoriety for their crimes or downplay crimes due to social desirability) so not sensible to fully rely on system which was formed by self-report data
• Can only be applied to certain crimes such as rape, arson and murder, these crimes reveal important details about suspect so limited in identifying criminals. However, Meketa 2017 applied this approach to burgulary. It has also showed an 85% rise in solved cases in 3 US states, so now has a wider application
• Categorisation of criminals is too simplistic hence isn't considered mutually exclusive. Some murder scenes may display a combination of organised and disorganised characteristics and as a result other researchers have formed more detailed models
• Helmes suggested four types of serial killer and having more categories is more useful and specific, but could be argued it's more complicated to assign criminals to as they may fall under multiple so therefore may not be the most reliable and detailed method in identifying a criminal