Offender profilling top down and bottom up approach

what is offender proffiling

Using the charecteristics of the crime nature to work out the charecteristics of the offender

Where did the top down approach originate

USA, by the FBI behavioural science unit

Where did the data to create the top down approach come from

gathered from in depth interviews from 36 sexually motivated serial killers.

Why is it called the top down approach

because the police use the 2 general catorgories to lead to the suspect. from the top down

What are the two catogories

organised and disorganised

What is an organised offenders features

-Evidence that the crime is planned

-Killer has a 'type' they target

-Little evidence of clues left behind

-high iq

-married or socially competent

What is a disorganised offenders features

- Little planning involved, spontaneous

-evidence left behind, body ect.

-low iq

- usually live alone and close to the crime

What are the four stages in working out which catogory the offender fits in to

Data assimilation

Crime scene classification

Crime reconstructor

Profile generation

What is data assimilation

data from the crime scene

What is crime scene classification

Decision if the crime is organised or disorganised

What is crime reconstruction

hypothesis made abt what would of happened at the crime scene

What is profile generation

Rough sketch of criminal, what there social groups and appearence is likely to be

Where was the bottom up approach made

UK by david canter

How did david canter challenge the top down approach, hence why the bottom up approach was created

interviewed 100 american serial killers and found no distinct patterns in behaviours between organised and disorganised killers

What is the bottom up approach based on

profile of the criminal is created through analysing data from specific crime scenes and patterns of behaviour that the offender may show

How does david canter use offender profilling according to the cognitive apporach

Based on the idea that staistical data can be used to make inferences on the schemas or ‘mental maps’ that the criminal may be in and therefore where he may live and work based on the crimes he has committed and where they have been committed

What are the key assumptions of investigative psychology

-Interpersonal coherence

-Significance of time and place

-forensic awareness

What is interpersonal coherence

The way the offender interacts with the victim, if the crime was agressive it can mean they are agressive in everyday life aswell

Significance of time and place

Positioning and timing of crimes gives clues to where the offender may live and work

What is Forensic awareness

interrogating suspects to understand how mindful they seem to be for 'covering their tracks’ and therefore if they may have previously been involved with the police

What is smallest space analysis

A computer program that identifies correlations within patterns of behaviour. Details of these offences can be used to reveal details of the offender

Why is geographic proffiling used

studying the spatial behaviour of the criminal, to identify their knowledge of the local area and from there an investigative psychologist can make inferences about the offendes, home, work, and social activity is

What is a centre of gravity

the area in the middle of where the crimes are committed which can be used to find where the offender lives/works

What is the jeopardy surface

An educated guess of where they think the offender is likely to strike next

What is the circle theory

The idea that the crimes occur in a specific spatial area that can be identified to find the criminal,

What are the two different circles

The marauder, and the commuter

What is the Mararuda

The offenders home is within the geographic of where the crimes are usually committed

What is the commuter

Offender travels to another area to commit their crimes and lives at a different home.

Why is this spatial understanding useful

can help the investigators understand if the crime was planned or more oppurtunistic

What is an example of succesful offender profilling

John duffy, aka the railway rapist. David canters profilling was extremely accurate narrowing down john duffy from 2000 suspects

What is a criticism of the top down approach's origins?

It is unscientific in its development as it was based on self report accounts from sexually motivated serial killers who may lie or overexagerrate due to social desirability or demand charecteristics

Why does the sample bring validity issues

It is small and unrepresentative and therefore can’t be applied to all crimes where they are not murders or sexually motivated

What is a weakness of the top down approach

It is too simplistic , canter found that when analysing serial killers he found that all of their crimes has a element of organisation to them so can’t suggest that criminals can be completely disorganised

What is a strength of the origin of the bottom up approach

It is scientific and uses statistical analysis aswell as psycholgoical theory (schemas). Canter and goodwin found that the circle theory to be accurate as they found 85% of offenders to live in the circles they created.

What is a a strength of the usefulness of the bottom up approach

Can be applied to a wide range of offences such as burglary ect as an offender profile can be made from many cases

Research that contradicts how useful the bottom up approach is in catching the offender in all crimes

Koscis found that only 50% of burglars lived in the circle they had made

What has survey evidence shown about the bottom up approach

Detectives who has used offender proffilling had found that it was useful in 83% of cases but only caught the offender in 3% of cases

What is a main issue to offender profilling, regarding the case of paul britton

That an offender profile can lead to ignoring potential suspects who do not fit in the profile created, ie Paul britton inaccurately profilled stagg in a murder when he was not the criminal, leading to the real criminal murdering again as they had ignored info out of the mental schema they had created