Making A Case - Creating A Profile

Question 0

What is top-down typology?

Answer 0

Imposing a big picture on a crime scene, named a typology, and looking for details in the scene which will support their hypothesis.

Question 1

Which was the study on top-down typology?

Answer 1

Canter, investigation of the organised/disorganised theory of serial murder

Question 2

What is the bottom-up approach?

Answer 2

Focusing on the small details at the bottom of your field of view and building up a picture from there. Everything is seen and processed.

Question 3

What was the aim of Canter’s study?

Answer 3

To test the reliability of organised/disorganised typologies

Question 4

What was the method of Canter’s study?

Answer 4

A content analysis using the psychometric method of multidimensional scaling was applied to 100 cases to find out if the features hypothesised to belong to each typology would be consistently and distinctively different. The cases came from published accounts of serial killers in the USA and were cross checked with court reports and officers where possible. The ire crime committed by each serial killer was analysed for the research. The Crime Classification Manual as useful to classify the crimes as organised or disorganised as far as was possible based on their replies to interviews.

Question 5

What were the results of Canter’s study?

Answer 5

Twice as many disorganised as organised crime scene actions wee identified, suggesting that disorganised offenders are more common or alternatively, easier to identify. Only two crime scene behaviours co-occurred in the organised typologies in a level significantly above chance; the body was concealed in 70% of cases and sexual activity occurred in 75% of cases. Similarly, only sex acts and vaginal rape occur in more than 2/3 if disorganised cases. Thus suggests that the actions that occur most often in serial murder are the consequence of most serial killings and not really distinctively different for each murderer. Smallest-space analysis failed to separate the two sets of variables. Instead the organised variables appeared central in the scattered plot, with disorganised variables spread widely around them.

Question 6

What was the conclusion of Canter’s study?

Answer 6

Instead of their being a distinction between two types of serial murder, all such crimes will have an organised element to them (as we might expect as the murderers were not caught after three killings). The distinctions between serial killers may be a function of the different ways in which they exhibit disorganised aspects of their activities. He suggests a better way to look at the individual personality differences between offenders.

Question 7

What is the study on bottom-up approaches?

Answer 7

Canter and Heritage, developments in offender profiling

Question 8

What was the aim of Canter and Heritage’s study?

Answer 8

To identify a behavioural pattern from similarity between offences

Question 9

What was the method of Canter and Heritage’s study?

Answer 9

A content analysis of 66 sexual offences from various police forces committed by 27 offenders was conducted to find 33 offence variables that were clearly linked to a potential behavioural characteristic (e.g. ‘surprise attack’). It was possible to say ‘yes’ or ‘no’ to each variable. (Sexual offences are chosen because there is a great deal of information available about the perpetrator’s actions.)

Question 10

What was the analysis used in Canter and Heritage’s study?

Answer 10

Smallest-space analysis

Question 11

What were the results of Canter and Heritage’s study?

Answer 11

Vaginal intercourse, no reaction to the victim, impersonal language, surprise attack and victim’s clothing disturbed were found to be central variables to the 66 cases of sexual assault. This suggests a pattern of behaviour where the attack is impersonal and the victim’s response is irrelevant to the offender.

Question 12

What were the conclusions of Canter and Heritage’s study?

Answer 12

Canter believes that the usefulness of this method is that all 5 aspects have now been shown to contribute to all sexual offences, but in different patterns for different individuals. This can lead to an understanding of how an offender’s behaviour changes over a series of offences, or more usefully still to establishing whether two or more offences were committed by the same person. This has become known his ‘5-factor’ theory.

Question 13

Which study was a case study?

Answer 13

Canter, the case of John Duffy

Question 14

What offences did John Duffy admit to committing?

Answer 14

25 offences between 1975 and 1986, which included 22 attacks on 22 women who were aged between 15 and 32 years and were targeted at railway stations in and around London and on Hampstead Heath in North London.

Question 15

What was Canter’s starting point for his case in John Duffy?

Answer 15

A violent crime can be seen as a transaction between at least two people and therefore must reveal something about the way the offender deals with people.
How prepared the offender is to try and relate to the victim = previous similar attempts at relationships
How much dominance is used = minimal amount needed to achieve the rape, indicating a weaker individual who was actually insecure

Question 16

Why was John Duffy eventually arrested?

Answer 16

He was already in the database and had already been interviewed in connection with an attack at knifepoint on his ex-wife. Thus was not associated despite similarities in attack styles as it was labeled a ‘domestic’. He was op1 of nearly 2000 suspects linked to the case by their blood group but he was the only one who lived in the Kilburn area of London predicted by the profile: he worked as a carpenter on the railway and he was the right age. A surveillance team watched him and he was arrested for his suspicious activities. A search of his house uncovered the unusual paper based string he used to tie up his victims.

Question 17

How did John Duffy differ from Canter’s profile?

Answer 17

He was shorter than his victims described and their varying versions of his appearance (ginger to back hair) ad one if the difficulties the police face in their original enquiry. (There was a possibility they were experiencing the ‘weapons effect’)

Question 18

What were some of the aspects of Canter’s profile for John Duffy?

Answer 18

Has knowledge of the railway system along which the attacks happen.
May have been arrested for something that had nothing to do with rape but with having been aggressive and under the influence if drink or drugs.
Has lived in the areas circumscribed by the first three cases since 1983.
His job most likely does not bring him into contact with the public.