Forensic Psychology Flashcards
(141 cards)
What does ‘forensics’ refer to?
Relates to the application of scientific methods and techniques to legal proceedings and the investigation of crime.
What is forensic psychology?
The practice of psychology applied to the law.
What is offender profiling? What is the main aim? When is it used?
An investigative tool that is intended to help investigators (the police) accurately predict the characteristics of unknown offenders.
-The main aim is to generate hypotheses about the probable characteristics of the offender (age, gender, background, occupation etc…) in order to narrow down the list of likely suspects.
-It is rare and professional profilers will only be called in to work alongside the police for serious and/or high-profile murder and rape cases - not used for less serious crimes.
What idea is offender profiling based on? What does it assume?
The idea that you can make assumptions about the characteristics of an offender by analysing the characteristics and particulars of the offence they commit.
-Assumes that crime is not random.
-Assumes that offenders have a distinctive way of committing crimes - ‘modus operandi’ (way of working).
-Assumes that offenders have a stable set of characteristics that will remain so over time - the principle of behavioural consistency.
What are the 2 approaches to offender profiling? What do they both involve?
1) Top-down approach - used in America.
2) Bottom-down approach - used in Britain.
-Although methods vary, the compiling of a profile in both approaches will involve the careful scrutiny of a crime scene and the analysis of other evidence (police reports, witness reports, crime scene photos, pathology reports etc…).
What is the top-down approach? How does it work? What is the basic premise?
The top-down approach (or the American approach) - where profilers start with a pre-established typology and work downwards to apply this to the crime scene and witness accounts in order to assign an offender to one of two categories/typologies.
-Starts with the big picture about the likely offender and then fills in the details.
-Attempts to fit the crime under one of the pre-established typologies based on the crime scene - hence top-down.
-The basic premise for this approach is that information left at the scene of a crime feeds back to the type of offender and tells us about their everyday behaviour - i.e how they offend may be consistent with parts of their life or everyday behaviour (not literally).
-The purpose of the approach is to detect signature aspects of the crime and similar patterns of modus operandi.
-Data can then be entered into a database and continually compared against other entries in relation to certain aspects of the crime.
How did the top-down approach originate? What research was conducted?
Originated in the USA as a result of work carried out by the FBI in the 1970’s.
-The FBI’s Behavioural Science Unit carried out in-depth interviews (qualitative data) with 36 sexually-motivated murderers - including Ted Bundy and Charles Manson - asked them about triggers and early warning signs.
-From the interview responses, as well as a thorough analysis of the details of their crimes, the offenders of serious crimes were categorised into organised and disorganised offenders (‘organised-disorganised’ typology) - each with certain characteristics.
-The characteristics of an offender could then be predicted by matching a crime scene to a pre-established typology.
What type of data is the top-down approach based on?
Top-down approach based on qualitative data.
What are the 2 types of offender?
1) Organised
2) Disorganised
-Based on the idea that the modus operandi of an offender generally correlates to a set of social and psychological characteristics.
What is an organised offender? What are the characteristics of an organised offence? What are the likely characteristics of an organised offender? What is their post-offence behaviour? Who is a classic example of an ‘organised’ killer?
An offender who shows evidence of planning, targets a specific victim and tends to be socially and sexually competent with above average intelligence.
-Planning is the key.
Offence (murder) characteristics:
-Planned/premeditated - e.g weapon hidden or materials brought to dispose of the victim’s body.
-Little evidence left at the scene - e.g might wear protective clothing to prevent blood splashes or DNA being left at the scene.
-Signs of self-control - e.g only stabbed once to kill, rather than inflicting multiple unnecessary wounds.
-Victim a targeted stranger - seeks to control them.
Likely offender characteristics:
-Above average IQ.
-Skilled occupation.
-Socially and sexually competent - charming.
-Married/cohabiting.
-Geographically mobile.
-Anger or depression at the time of offence.
-Likely kills after some sort of critical life event - e.g Ted Bundy’s girlfriend broke up with him.
Post-offence behaviour:
-Returns to the crime scene.
-Volunteers information.
Example - Ted Bundy:
-During the 1970’s, Bundy raped, tortured and brutally murdered over 30 women across 7 states.
-Bundy was charming and highly intelligent - traits he used to win the trust of his victims.
-While a student, Bundy had a serious relationship with a young woman who ultimately broke up with him - this was a pivotal moment in his descent into becoming a serial killer.
-Many of Bundy’s later victims resembled his girlfriend.
What is a disorganised offender? What are the characteristics of a disorganised offence? What are the likely characteristics of a disorganised offender? What is their post-offence behaviour?
An offender who shows little evidence of planning, randomly selects a victim and tends to be socially and sexually incompetent with lower-than-average intelligence.
-Impulsivity and recklessness is the key.
Offence (murder) characteristics:
-Unplanned/spontaneous - e.g driving in their car and see a potential victim.
-Evidence left at the scene - little attempt to hide.
-Minimum use of self-control or signs of constraint - e.g smashes window, rather than carefully removing a pane of glass.
-Victim randomly selected.
Likely offender characteristics:
-Lower-than-average IQ.
-Low skilled occupation or unemployed.
-Socially and sexually incompetent.
-Lives alone.
-Often lives and works near the crime scene.
-Fear or confusion at the time of the offence.
-Physically or sexually abused in childhood.
Post-offence behaviour:
-Returns to the crime scene to relive the offence.
-May keep a diary or the news articles of the incident.
What are the 4 stages of constructing of an offender profile using the top-down approach?
Constructing an FBI profile:
1) Data assimilation - information and evidence from multiple sources is gathered and reviewed (i.e police reports, witness reports, crime scene photos, pathology reports).
2) Crime scene classification - classified as either organised or disorganised.
3) Crime reconstruction - hypotheses in terms of the sequence of events and the victim’s behaviour are generated.
4) Profile generation - hypotheses related to the likely offender in terms of their demographic, physical characteristics and behavioural habits are generated - always compared to the typologies. Data can then be entered into a database and continually compared against other entries in relation to certain aspects of the crime.
The key thing with the top-down approach is that the typologies are pre-established and then applied to fit the crime scene - the crime scene only informs a pre-established category of profile rather than it building an independent profile in its own right.
What are the strengths and limitations of the top-down approach?
Strengths:
-Enormously influential as the first systematic approach for profiling offenders in serious crimes - adopted by many law enforcement agencies all over the world.
-Allows offences to be linked by offender typologies, thus facilitating predictions about the timeframe and nature of the next attack.
-Challenged the stereotype that investigators may have held about serious offenders being one thing - e.g Clarke and Morley (1998) interviewed 41 convicted rapists responsible for over 800 offences - found that they were typically average men living in normal family circumstances and in skilled employment (contrary to the stereotype of an inadequate loner).
Limitations:
-A typological approach assumes that offenders are one thing or the other and that this is stable over time - i.e behavioural consistency. Situationist psychologists argue that people’s behaviour is much more driven by the situation rather than by personality or the type of offender they are.
-Wilson et Al (1997) - suggests that most offenders show both organised and disorganised criminal behaviour and may shift between the, from crime to crime - so more of a continuum.
-Hypotheses generation subjective. Different profilers may reach different conclusions from the same evidence.
-Cannot establish a suspect in its own right - can only provide an outline or ‘sketch’ of the type of offender. Could result in innocent parties being implicated or arrested.
-Small and exclusive sample - the methods and motives of the 36 interviewed are of a very rare type of offender - may not be able to generalise to other offenders.
-Can only be applied to sexually motivated murder - although can be adapted to burglary in some cases. Canter et Al criticised the sample for its size and lack of randomness.
-Not scientifically verifiable - the vagueness of the profiled can lead to the ‘Barnum effect’, where the personality criteria are general enough to be applied to anyone.
-No ethical standards for the practice of profiling.
What is the bottom-up approach? Who developed it How does it work? What is the basic premise?
The bottom-up approach (or the British approach) - where profilers start with the evidence at the crime scene and work up to develop hypotheses about the likely characteristics and background of an offender by systematically analysing evidence.
-Developed by David Canter (1990) - said profiling needs to be scientific.
-Doesn’t begin with fixed typologies or theories - unlike the top-down approach.
-Starts with small details (the raw data) which are rigorously scrutinised to build up the bigger picture of a conclusion about the offender - e.g physical evidence - forensics, DNA.
-Assumes that offenders leave a ‘psychological fingerprint’ of unique and consistent behaviour.
-Data-driven so doesn’t rely on a subjective interpretation of an offender or crime scene - uses scientific and quantitative data - e.g forensics and DNA.
-This data is then inputted into a database and scientific and statistical predictions are made based on the evidence from other crime scenes.
What type of data is the bottom-up approach based on?
Bottom-down approach is based on quantitative data.
-More objective and reliable than top-down approach - more scientific.
-Helps to show how and why variations in criminal behaviour occur - not interested in subjective constructions about what happened.
What are 2 forms of the bottom-up approach?
1) Investigative psychology
2) Geographical profiling
-No pre-established typology - instead develops a data-driven profile.
*Both likely to come up in exam
What is geographical profiling? What does it involve? What principle is it based on?
A form of bottom-up profiling that uses information about the location and timing of linked crime scenes to make inferences about the likely home, work or operational base of an offender - (crime mapping - linked crime scenes plotted to create a ‘jeopardy surface’).
-Concerned with the where, rather than the who or the why.
-Based on the principle of spatial consistency - that people commit crimes within a limited geographical area. Offenders more likely to commit crimes in areas that they know.
-People reveal themselves through their chosen location as much as they do through their behaviour.
-Implies that an offender’s operational base and possible future offences can be revealed by the geographical location of their previous crimes.
-A hypotheses can be created on how the offender is thinking as well as their modus operandi.
-Can be used in conjunction with psychological theories (i.e those used in investigative psychology).
What theory did Canter and Larkin (1993) propose? What is the difference between the marauder and the commuter offender?
Canter and Larkin (1993) - Circle theory of environmental range.
-Proposes that offenders commit crimes within an imagined circle.
-This circle forms the spatial pattern of offending.
-The offender’s base is the middle of the circle / spatial pattern.
-The spatial decision-making (where) of an offender can offer insight into the nature of the offence (modus operandi) - planned or opportunistic, as well as revealing other important factors such as modes of transport, age, employment status etc…
2 types - based on the distribution of offences (not pre-established):
1) Marauder - an offender whose home is within the area the crimes were committed (most common - 91%).
-Their base and anchor point (middle of the circle) is home.
-Bounded by psychological barriers.
-Easier to geographically profile.
2) Commuter - an offender who travels to another area to commit a crime.
-Their base (middle of the circle) is away from home which may even be outside the circle.
-They lack an anchor point and commit crime over large areas - may not even operate within a circle.
-No psychological boundaries.
-Involves hunting strategies.
-Harder to geographically profile.
What computerised system did David Canter develop for geographical profiling?
Canter (2003) - ‘Dragnet’ developed.
-Used information about the location of offences to predict where an offender is likely to live.
-Remember, the bottom-up approach is data-driven.
What is investigative psychology? What does it involve? What principle is it based on?
A form of bottom-up profiling that matches details from the crime scene with statistical analysis of a typical offender’s patterns of behaviour based on established psychological theories - the aim is to establish patterns of behaviour that are likely to occur or co-exist across crime scenes and to use this to link a series of offences to one likely offender (‘case linkage’).
-Grew out of geographical profiling.
-Based on the principle of interpersonal coherence - that the way an offender behaves while committing a crime, including the way they ‘interact with the victim, may reflect the way they behave and interact in their everyday life.
-The concept of ‘forensic awareness’ must also be taken into account - if the person has been subject to police interrogation before, their behaviour may denote how mindful they are of covering their tracks.
-A statistical database is established which then acts as a base for comparison.
What series of London rapes and murders was David Canter asked to help investigate? How did Canter involve both forms of the bottom-up approach?
‘The Railway Rapist’ John Duffy.
-John Duffy carried out 24 sexual attacks and 3 murders of women near railway stations in North London in the 1980’s.
-Using crime scene evidence and information, Canter applied statistically analysed typical behaviour (based on psychological theories) to suggest where the offender was living, his type of job, his social life and his history of offending.
-Canter also analysed geographical information from the crime scenes of the previous attacks.
-Canter drew up a profile of the offender which proved surprisingly accurate as police began covertly observing Duffy - he lived near the area, was separated from his wife, had attacked his wife.
-This led (indirectly) to his eventual arrest and conviction - Canter’s contribution simply narrowed down the list of suspects to save the police time (so useful, but didn’t actually identify the offender directly).
Used geographical profiling and investigative psychology.
What are the strengths and limitations of the bottom-up approach?
Strengths:
-Lundrigan and Canter (2001) - using smallest space analysis - a technique that identifies correlations across different samples of behaviour - it was revealed that there was spatial consistency in the behaviour of the killers involved in 120 murder cases. There was a ‘centre of gravity’ as the body sites created a circular effect around the operational base - more noticeable for marauders.
-Canter and Heritage (1990) - smallest sample analysis used to identify several common behaviours common in different samples of behaviour across 66 sexual assault cases (e.g use of impersonal language and lack of reaction to the victim) and each individual displayed a characteristic patterns of such behaviour - this supports interpersonal coherence as the basis for investigative psychology. Also helps establish case linkage.
-Rossmo said that the bottom-up approach helps to target individuals that otherwise might not have been identified.
-More holistic than top-down approach - draws on a variety of psychological methods
-Increased validity.
-Statistical basis makes it more objective and reliable than the top-down approach.
-Can be applied to a wide range of offences.
-Copson (1995) - surveyed 48 police departments - found that the advice of the profiler was judged to be ‘useful’ in 83% of cases - suggests it’s a valid investigative tool.
Limitations:
-Geographical profiling and investigative psychology may not be sufficient on their own - they are reliant on access to and quality of data. This means they are not always accurate and can’t be used as standalone tools that the police can use.
-Ainsworth (2001) - the time of the offence and the age/experience of the offender are equally important in successfully capturing an offender - geographical information alone may not be enough.
-Case linkage is dependent on already solved historical crimes in a database - this means that investigative psychology is not really useful for crimes that have few links.
-‘Marauders’ and ‘commuters’ too generic - Canter and Larkin (1993) found that 91% were marauders.
-Copson (1995) - only 3% said it actually helped to catch the correct offender.
-An imagined circle is problematic - so still not completely scientific.
-Useful in narrowing down, but not for actually identifying.
What debate do biological explanations for offending behaviour fall into?
Nature-nurture - the question of whether criminals are born or made is certainly under this debate.
-Biological explanations for offending can be both nature and nurture.
-Nature = criminal behaviour may be inherited.
-Nurture = criminal behaviour may be due to acquired abnormalities in brain structure.
What are the 2 types of biological explanations for offending behaviour?
1) An historical approach - Atavism / Atavistic form.
2) Genetic and neural explanations - a more modern approach. (*due a question).