forensic psychology Flashcards
what is offender profiling?
- An investigative tool employed the police when solving crimes, to narrow the list of likely suspects
professional profilers will often be called on to work alongside the police, especially when it comes to high profile cases - methods can vary but the main methods involve careful scrutiny of the crime scene and analysis of other evidence (including witness reports)
all of this is done to get an idea of the offender (age, background, occupation)
what is the American approach
The top down approach originated in the US as a result of the work carried out by the FBI in the 1970s
they carried out research adn produced data from 36 sexual serial offenders, including ted bundy and charles manson
they determined that each characteristic could be determined inot organsied and disorganised and that from this, we can predict other characteristics which then allows us to find the offender
offender profilers who use the top down approach with collect details about the murder (characteristics of the murderer, the crime scene etc) and then decide on the category that fits the data the best
what is organised and disorganised types of offenders
this is based around the idea that experienced offenders will often have signature “ways of working” (their modus operandi) which generally correlate with a particular set of characteristics
organised offenders show evidence of having planned the crime in advance - the victim is deliberately targeted and it is often a much more skilled act
disorganised offenders are often spontaneous and have little lanning which causes there to be evidence left around
what are the stages of Constructing a FBI profile data
data assimilation - the profilers review the evidence (crime scene photographs, pathology reports etc)
crime scene classification - either organised or disorganised
crime reconstruction - hypothesis in terms of sequence of events, behaviour of victims etc
profile generation - hypotheses related to the likely offender e.g demographic background, physical characteristics, behaviour etc
what is the aim of the bottom up approach
- The aim is to generate a picture of the offender (characteristics, routine behaviour, social background etc) through analysis of the crime scene
- unlike the top down approach it does not begin with fixed typologies
what are the key features of the bottom up approach?
investigative psychology
geographical profiling
what is investigative psychology
patterns that occur or co - exist across crime scenes are used to generate data about the offender. It is based on the psychological theory of matching behavioural patterns to generate a database that acts as a baseline for comparison. specific details can be compared to reveal characteristics of the offender
what are the characteristics that may reveal an offender in the bottom up approach
- interpersonal coherence- how the offender interacts with the
- crime scene & victim may reflect their everyday behaviour
significance of time and place - geographical profiling
- crime scene & victim may reflect their everyday behaviour
- forensic awareness - behaviour may be indicative of previous criminal experience
what is routine activity theory?
- cohen and Felson (1979)
- crimes occur when 3 circumstances coincide:
- a motivated offender
- a suitable (and vulnerable) victim
- absence of a capable guardian
- a motivated offender
- criminal offences are an extension of the offenders normal activities, so will occur in places the offender makes regular use of
routine activity theory relies on the same rational choice methodology as situational crime prevention techniques
what are the criticisms of routine activity theory?
they may not use the same rationale as the person implementing the security measures. they may not even be aware of the situational crime prevention technique put into effect. they may be under the influence of drugs or alcohol or for whatever reason they may simply not care about the security measures
what is smallest space analysis?
- this is a statistical technique developed by Canter
- data about many crime scenes and offender characteristics are
- correlated so that most common connections can be identified
-Salfati and Canter (1999) analysed the co-occurrence of 48 crime scenes and offender characteristics from 82 murders and identified 3 underlying themes:- instrumental opportunistic: “instrumental” refers to using the murder to obtain something or accomplish a goal , “opportunistic” refers to the offender taking the easiest opportunities
- instrumental cognitive: a particular concern about being detected and therefore more planned
- expressive impulsive: uncontrolled, in the heat of strong emotions, may feel provoked by victim
what is geographical profiling?
- Rossmo (1997) stated that the geographical location of their previous reveals an offender’s operational base of possible future offences.
- uses the location of linked crimes to make inferences of the the likely home (crime mapping) based on the principle of spatial consistency that people commit crimes in a limited geographical space
- used in conjunction with psychological theory e.g investigative psychology to create hypotheses about their modus operandi (MO)
what is mental maps?
- individuals construct mental maps of the areas they know
assumption is that offenders will restrict their “work” to familiar geographical locations, so the spatial pattern of behaviour - provides a “centre of gravity” for investigators to locate their base
- These are not absolutely accurate. they embody the person’s experience and perspective on the area
what is a marauder?
the offender operates in close proximity to their home base
what is a commuter?
the offender is likely to have travelled a distance away from their usual residence
why is knowing whether the offender is a marauder or commuter important?
such spatial decision making can help investigators make insights about the nature of the crime e.g opportunistic as well as features of the offender e.g mode of transport favoured, employment, approximate age
what is criminal geographical targeting (CGT)?
- This is a computerised system developed by Kim Rosso and based on their own formula
- the formula produces a three- dimensional map displaying spatial data related to time, distance and movement to and from crime scenes
- This map is called a jeopardy surface. The different colours indicate likely closeness to crime scene
weakness of the bottom up approach: other factors are important
- location is important, but there are other factors that need to be taken into account, such as their psychological characteristics
-concentrating on location may cause an investigator to miss important information if used in isolation
strength of the bottom up approach: evidence supporting geographical profiling
- Lundrigan and Canter (2001) collated information from 120 murder cases involving serial killers in the USA.
- Analysis revealed spatial consistency in the behaviour of the offenders
- The effect was more noticeable for offenders who travelled short distances (marauders)
- this supports Canter’s claim that capital information is a key factor in determining the base of an offender
strength of the bottom up approach: based on research and statistical likelihood
- It is based heavily on research and statistical likelihood. This means that it is seem to be more scientific that top down approach
- this use of statistics and theory has removed intuition of the profiler from the process, which is argued to make it more reliable
weakness of the bottom up approach:
mixed results for profiling
- despite the successes, there have been some significant failures (e.g rachel Nickell) Copstom (1995) surveyed 48 police formed and found that the advice provided but the profiler was useful in 83% of cases, but only in 3% did it lead to accurate identification of the offender
- Kocsis (2002) chemistry students produced more of an accurate profile on a solved murder case than experienced detectives
what are the 3 main biological explanations of crime?
atavistic form
genetic
neural
what did Lombroso’s suggest about criminals?
- criminals were genetic throwbacks - a primitive sub species who were biologically different to non criminals
- He proposed that, as criminal behaviour is innate, an offender is not responsible for their actions
what are the characteristics for criminals according to Lombroso?
characteristics:
- narrow, sloping brow
- strong prominent jaw
- high cheekbones
- facial asymmetry
- dark skin
- existence of extra toes, nipples of fingers