Forensics - Offender Profiling Flashcards
What does Offender Profiling attempt to do?
Attempts to develop a set of characteristics of people that commit a specific crime.
What are the two main methods of offender profiling?
Top-down & Bottom-up approach
What is the purpose of offender profiling?
- Helps police in catching the offender
- Police can look at profile and focus resources and time on specific types of individuals
Who first developed the top-down approach?
The FBI (America)
Who did the FBI examine and interview?
36 people who had been convicted of heinous crimes such as serial killing or rape murders. They did this to create a general description of people who commit these types of crimes.
What categories were the 36 convicted individuals split into?
Two groups=
- organised
- disorganised
What are organised criminals classified as?
- Intelligent
- socially and sexually competent
- did not live alone
- planned their attacks
What are disorganised criminals classified as?
- not as intelligent
- socially and sexually incompetent
- lived alone
- were spontaneous in their attacks
What is a strength of the top down approach?
- Using information gathered from interviews, the FBI investigators were able to examine new crime scenes with insight into the behaviour of the individual
What is a limitation of the top-down approach?
- The crime is self reported which means the research lacks validity
- The sample is completely restricted to these 36 convicted felons, this means their findings cannot be generalised to the public.
Who came up with the bottom-up approach?
David Canter (1994)
Who used the bottom-up approach?
British investigators
What does geographical profiling involve?
Analysing the locations of a connected series of crimes and considers where the cries were committed , the spatial relationships between different crime scenes and how they might relate to an offender’s place of residence.
What type of psychology does geographical profiling use?
Investigative psychology
What does investigative psychology involve?
It applies psychological theories and research to criminal investigations
Why is the bottom-up approach called such?
The focus is on the individual person committing the crime and the unique circumstances in which the crime took place.
Who studies the four main stages of the top-down approach?
Douglas et al (1986)
What are the six main stages of the top-down approach?
- Profiling inputs
- Decision process models
- Crime assessment
- Criminal profile
- Crime assessment
- Apprehension
The bottom-up approach uses geographical profiling. What five characteristics should be in the profile?
- Personal characteristics
- Criminal history
- Residential location (circle theory)
- Domestic and social characteristics
- Occupational and educational history
TDA = What happens in the profiling inputs stage?
The data collected includes a description of the crime scene , background information about the victim, and details of the crime itself . All information should be included
TDA = What happens at the decision process models stage?
The profiler starts to make decisions about the data and organises it into meaningful patterns i.e murder type, time factors and location factors
TDA = What happens at the crime assessment stage?
The crime is classified as either organised or disorganised
TDA = What happens at the 4. criminal profile stage?
A profile is now constructed of the offenders which included hypotheses about their likely background, habits and beliefs of the offender. These details are used to work out a strategy for the investigation to catch the offender
TDA = What happens at the 5. crime assessment stage?
A written report is given to the investigating agency and persons matching the profile are evaluated
TDA = What happens at the 5. apprehension stage?
The entire profile-generating process is reviewed to check that at each stage the conclusions were made legitimate, i.e valid and consider how the process may be revised for future cases.
Define the ‘top down approach’
An analysis of previous crimes creates a profile of a likely offender . A profiler uses this knowledge to narrow the field of possible suspects . Unlike the bottom up approach, the top-down approach relies on the intuition and beliefs of the profiler.
Is the top down approach useful?
Police who have used FBI methods believe it is useful. 82% of 184 US Police officers said the technique was operationally useful and over 90% said they would use it again.
Why is the basis of the method flawed? TDA
Based on the interviews with 36 of the most dangerous and sexually motivated murderers, including Ted Bundy. The data was used to identify the key characteristics that would help police ‘read’ a crime scene . This in itself is doubtful as such individuals are not likely to be the best source of reliable information . In addition, their approach and rationale may be quite different to more ‘typical’ offenders . Six stage process can have changes made to it.
Explain the difficulty in distinguishing between organised and disorganised types of offender
Turvey suggests that such a dichotomy is false as it is more likely to be a continuum rather than two distinct categories . This is further supported by the fact that descriptions may at best be generalisations as they use phrases such as ‘‘tends to be’’ and therefore have little utility.
David Canter provided little evidence that the classification has little basis in reality . They analysed 39 aspects of serial killings committed by 100 US serial killers. Their analysis revealed no clear division between organised and disorganised types of offender. Instead they found a number of subsets of organised type-crimes and little evidence for disorganised types.
What is the bottom up approach?
A data-driven approach where statistical techniques are used to produce predictions about the likely characteristics of an offender.
What are the main 3 features of the bottom up approach?
Interpersonal coherence, forensics awareness, smallest space analysis
What is interpersonal coherence?
People are consistent in their behaviour and therefore there will be links with elements of the crime and how people behave in everyday life. At the same people’s behaviour changes over a four-year period might offer further clues
What is forensic awareness?
Certain behaviours may reveal an awareness of particular police techniques and past experience for example, Davis found that rapists who conceal fingerprints often had previous conviction for burglary.
What is smallest space analysis?
A statistical technique developed by Canter. Data about many crime scenes and offender characteristics are correlated so that most common connections can be identified.
Explain circle theory
David Canter proposed that most offenders have a spatial mindset - they commit their crimes within an imagined circle
What are marauders?
The offenders home is within the geographical area in which crimes are committed
What are commuters?
The offender travels to another geographical area and commits crimes within a defined space around which a circle can be drawn
Explain the scientific basis of the bottom-up approach
BU is thought to be more scientific than TD because of the use of objective statistical techniques and computer analysis. However such techniques are only as good as the data that is input. One issue is that the data that is used to drive such systems is only related to offenders who have been caught, and therefore this tells us little about patterns of behaviour related to unsolved crimes.
Is investigative psychology useful?
Copson surveyed 48 UK police forces using investigative profiling and found that over 75% of the police officers questioned said that profilers’ advice had been useful. However only 3% said the advice has helped identify the actual offender - nevertheless most said that they would use a profiler again. It should be pointed out that by no means all police use profilers . In Copson’s study , in one year , the max number of crimes per year where profiling was used only 75 cases.
Is circle theory successful?
Canter and Larkin studied 45 sexual assaults and showed support for their model by distinguishing between marauders and commuters . However 91% of the offenders were identified as marauders - if almost all offenders are marauders , then the classification doesn’t seem particularly useful.
Oversimplified
Is geographic profiling generally successful?
Rossmo is one of the key supporters of the geographical approach and claims that while it may not solve crimes specifically, it can be useful in prioritising house-to-house searches or identifying a geographical area where DNA could be collected.
Why is there a big danger in sticking too closely to any one profile ?
The murder of Rachel Nickell demonstrates the danger. IN 1992 the 21 year old mother was stabbed to death . The forensic psychologist Paul Britton helped the police to create a profile which led to the identification of Colin Stagg. It later turned out , after spending a considerable amount of time and money trying to convict Colin Stagg that the actual murderer was Robert Napper, who had been ruled out because he was taller than the picture given in the profile.
