Offender Profiling - Bottom Up Approach Flashcards
What is the bottom up approach?
- Sometimes known as the British Approach
- It makes use of past data on similar crimes committed in order to build a picture of the offender (characteristics, behaviours, social background)
- Investigators will conduct a systematic analysis of the crime scene and compare with this historical data in a computer data base
- Does not use fixed typologies - instead is data driven and emerges as the investigator conducts a rigorous scrutiny of the details of the offence
- This approach is therefore much more grounded in psychological theory
What is investigative psychology?
- Attempt to apply statistical procedures, alongside psychological theory to try and establish patterns of behaviour that are likely to occur
- Develops a statistical database which acts as a baseline for comparison
What is interpersonal coherence?
The way an offender behaves at the scene, including how they ‘interact’ with the victim
What is the significance of time and place?
This may indicate where the offender is living
What is forensic awareness?
Describes those individuals who have been the subject of police interrogation before, their behaviour may denote how mindful they are of ‘covering their tracks’.
What is Geographical Profiling?
A form of bottom-up profiling based on the principle offences are revealed by the geographical location of their previous crimes
What is spatial consistency?
People commit crimes within a limited geographical space
What is Crime mapping?
Geographical profiling uses information about the location of linked crime scenes to make inferences about the likely home or operational base of an offender
What is Modus Operandi?
A particular way or method of doing something
What did Canter and Larkin develop?
The circle theory which proposed two models of offender behaviour
What is a marauder?
Someone who operates in close proximity to their home base
What is a commuter?
Someone who is likely to have travelled the distance away from their home base/own residence
What was David Canter and John Duffy’s ‘Railway Rapist’ study?
Aim - to assist police with the capture of the ‘railway rapist’ by building an offender profile
Method - using evidence of the bottom - up approach, canter put together a profile = this included both personality and geographical characteristics
Results - his profile suggested that the individual had a poor past history with women, was in his mid to late twenties and was a semi-skilled labourer. These matched the profile of John Duffy, 29 years old, separated from wife, was abusive during marriage.
Geographically, Duffy fit Canter’s profile, suggested the offender would have knowledge of the railways and lived ear to the crime scenes, as Duffy has worked for the railways as a carpenter and living centrally to the clusters of crime committed.
Conclusion - Although Canter’s profile wast completely accurate, he created a sufficient profile for the police to question Duffy and place him under arrest. Sometime after his arrest and imprisonment, Duffy gave up the name of his accomplice David Mulachy Sanford both are serving life prison terms.
Explain Gary Corpson’s (1995) 48 police departments study
He found that the advice provided by the profiler was 83% useful in cases. However, the same study revealed that only 3% of cases did it lead to the accurate identification of the offender.
This suggests that whilst offender profiling may be somewhat useful, other police techniques are likely more important when actually catching a criminal.
Explain Canter and Heritage’s (1990) analysis of 66 sexual assault cases
They identified common behaviours in assault (using impersonal language, lack of reaction to the victim). They also discovered that each individual criminal has their own patter of behaviours at the crime scene.
This can therefore hemp to establish whether two or more offences were committed by the same person (‘case linkage’), showing that the bottom-up approach is useful and a valid way of profiling criminals.
What was Lundrigan and Canter (2001) find after collecting information from 120 murder cases involving US serial killers?
Using a smallest space analysis they found spatial consistency in the behaviour of the killers. This means that each individual killer disposed of bodies in a different direction, ultimately creating a ‘cirlce’, where their home base was at the centre. This was more noticeable in marauders than commuters.
This shows that geographical location, such as location of body disposal, an be used to identify the location of an offender, leading to higher crime solving rates, making the bottom-up approach an effective method for criminal profiling.
Explain the study on Rachel Nickell’s (1992) stabbing (47 times) and sexual assault on Wimbledon common
The investigation from the profiler led to the police targeting Colin Stagg. An undercover police women spent 5 months feigning romantic interest with Stagg, to try and get a confession from him. When the case went to court it was thrown out due to lack of evidence. In 2008, Robert Napper was eventually convicted of Nickell’s murder. He was initially ruled out of the enquiry because he was several inches taller than teh profile.
This shows that profiles are not always completely accurate and that, over reliance on profiles, can lead to wasted police time and incorrect arrests, possibly allowing the criminal to go free.
