Forensic Psychology Flashcards
Crime
An act that breaks the law and can result in some form of punishment
Why is crime a social construct?
Laws often change and there are cultural and historical differences in definitions of crime.
For example, homosexuality was only decriminalised in 1967 in England.
Offender profiling
An investigative tool used by professionals to help them to accurately predict the traits and characteristics of a suspect.
The top-down approach
Profilers start with a pre-established typology (category) and work down to lower levels in order to assign offenders to one of two categories based on witness accounts and evidence from the crime scene.
Where did the top-down approach originate from?
Originates from the work of the FBI in 1970s America
Two offender categories in the top-down approach
Organised offender and disorganised offender
Characteristics of an organised offender
- Evidence of planning: little evidence/clues left behind at the crime scene
- Victim appears to be chosen or even known to the offender
- Likely to be in a skilled, professional occupation
- Average or higher intelligence
- Likely to have experienced inconsistent discipline in their childhood
Characteristics of a disorganised offender
- Little evidence of planning: signs of spontaneity, likely to leave evidence behind
- The victim appears to be randomly chosen
- Unlikely to have success in employment
- Below average intelligence
- Likely to have experienced harsh discipline in their childhood
What evidence was the top-down approach based on?
FBI’s Behavioural science unit conducted extensive interviews with 36 sexually motivated serial killers to understand the patterns and behaviours of offenders.
What was the aim of the interviews with 36 sexually motivated serial killers?
To develop specific details of crimes and crime scenes so that database of common characteristics could be developed.
Strength of the top-down approach interviews
It produced qualitative data which generated rich, detailed information on the patterns and behaviours of offenders
Weakness of the top-down approach interviews
Small sample size
Unrepresentative sample: may only be applicable to murderers and rapists; hard to generalise to other non-serious crimes such as petty theft
Four main stages in the construction of an FBI profile (Howitt, 2009)
- Data assimilation: the profiler reviews the evidence eg crime scene photographs
- Crime scene classification: as either organised or disorganised
- Crime reconstruction: hypotheses in terms of sequence of events, behaviour of the victim, etc
- Profile generation: hypotheses related to the likely offender eg of demographic background, physical characteristics, behaviour etc
Limitation of the top-down approach
One limitation of the top-down approach is that it’s based on flawed evidence.
The categories were based on interviews conducted with 36 sexually motivated serial killers. The sample is small and unrepresentative, meaning it may be difficult to generalise these categories to other non-serious crimes such as petty theft that may exhibit different characteristics.
This suggests the evidence that the top-down approach is based on has low population validity and thus undermines this approach. It may only be appropriate for profiling offenders of particular crimes such as murder or rape and not theft or arson.
However, it has been argued that it is possible to adapt it for other kinds of crimes, including burglary. Meketa (2017) reports that top-down profiling has recently been applied to burglary. This led to an 85% increase in solved cases in three US states. This suggests that top-down profiling has wider application that it was originally assumed.
Strength for organised offender category (top-down approach)
There is evidence to support a distinct offender category.
For example, David Canter et al. (2004) conducted an analysis of 100 US murders each committed by a different serial killer. A statistical analysis was used to assess the co-occurrence of 39 aspects of serial killings, which included things like the form of murder weapon used and the cause of death.
This analysis revealed that there does seem to be a subset of features of many serial killings which matched the FBI’s typology for organised offenders, thus increasing the validity of the top-down approach.
However, many studies suggest that the organised and disorganised categories may not be mutually exclusive and that the categorisation may be too simplistic. For example, Godwin (2002) argues that it’s difficult to classify killers as one or the other type. A killer may have multiple contrasting characteristics, such as high intelligence but commits a spontaneous murder and leaves the victim’s body at the crime scene. This suggests that the typologies model is too simplistic and lack validity as it assumes that there are only two types of offenders and can only be used to explain certain crimes.
Who developed the bottom-up approach?
David Canter
The bottom-up approach
It is grounded in theory and is a ‘data-driven’ approach, which relies heavily on statistical databases. Evidence is used to create hypothesis and theory.
There are two elements of bottom-up offender profiling:
1. Investigative psychology
2. Geographical profiling
Investigative psychology
- Involves using statistical analysis of the crime scene.
- Details of the crime scene are statistically analysed, and added to larger statistical data set of crimes already recorded by police.
- Details of the crime are then compared to this larger statistical data (database), which helps to generate data about the offender (e.g. typical offender behaviour patterns and potential relationships between crimes).
Key assumptions in investigative psychology (which are also informed by data) that help build up the profile
- Forensic awareness
- Time and place
- Interpersonal coherence
Key assumption of investigative psychology: Forensic awareness
Details of the crime scene can be used to determine whether the offender has any knowledge about how criminal and police investigations work (i.e., did they cover their tracks?)
Key assumption of investigative psychology: Time and place
Time and place of offence may reveal information about where offender lives (their base), mode of travel or whether they are employed/unemployed
Key assumption of investigative psychology: Interpersonal coherence
The way the offender behaves at the crime scene and how they interacted with the victim may reflect their behaviour in everyday situations.
Geographical profiling
Refers to the analysis of crime locations and times to identify patterns of an offender.
- Analyses the spatial relationships between linked crime scenes to reveal clues about offenders life, job, where they live, where they socialise, mental map of offender.
- Use data from crime scene used alongside local crime statistics, local transport, etc.
- It links to Canter’s Circle Theory, which states offenders have a spatial mindset and commit crimes within a geographic circle they are familiar.
- Profilers are able to establish whether an offender is a commuter or a marauder.
- The analysis of locations also allows profilers to establish a jeopardy circle based on emerging patterns.
Jeopardy surface (circle)
Where an offender might strike next
Centre of gravity
Where an offender is likely to be based
Commuter
Offender travels from their home to a familiar area then commits crimes within a criminal range of that area.
Marauder
Offender commits crimes within a criminal range from their own home
Strength of the bottom-up approach to offender profiling: real world application
P: it has been used successfully to catch offenders.
E/E: In 1986, Canter used this approach to provide an offender profile for the ‘Railway Rapist’ (John Duffy) who had sexually assaulted and murdered women near railway stations in London. After a conviction in 1988, it was confirmed that 12 out of the 17 characteristics in the profile provided by Canter were accurate.
L: This confirms that the bottom-up approach to offender profiling does have useful applications in fighting crime.
Strength of the bottom-up approach to offender profiling: more useful than top-down offender profiling
P: more useful in a wider range of criminal behaviours than top-down offender profiling.
E/E: The categories in the top-down approach are based on interviews with 36 sexually motivated serial killers.The sample used is small and unrepresentative, thus it may be limited to extreme offender behaviours such as rape and murder. The bottom-up approach is ‘data-driven’ so it can be applied to more types of crimes like theft.
L: This suggests that the bottom-up approach is a more suitable method of offender profiling as there are more opportunities for it to be applied.
Strength of the bottom-up approach to offender profiling: highly scientific approach to offender profiling
P: It is deemed to be a highly scientific approach to offender profiling.
E/E: Since the foundation of this approach is data, and decisions and assumptions are data-driven, the approach is objective and refrains from forming profiles with hunches and subjective interpretations of crime scenes. This contrasts with the top-down approach to offender profiling, which is not reliant on data and instead is built with a hypothesis about offender behaviour based on the templates derived from subjective interviews of extreme offenders.
L: This increases the credibility of the bottom-up approach
Limitations of offender profiling: issues
P: One weakness of the offender profiling is that it is not always accurate.
E/E: In the case of Rachel Nickel, police arrested an innocent man named Stagg based on an offender profile. This illustrates the fact that just because someone fits a profile, it doesn’t mean that they are the offender. Further evidence that supports this view comes from Copson (1995) who surveyed 48% police departments and found in only 3% of cases did the offender profiling lead to the accurate identification of the offender.
L: This suggests profiling can help narrow down a list of suspects and give a lead in an investigation but it will not deliver the actual suspect, and therefore highlights the potential dangers of how profiling can be misused.