Problems with defining crime
Historical and cultural issues. For example laws on homosexuality and marriage have changed over time and differ from place to place
Ways of measuring crime
Official statistics
Victim surveys
Offender surveys
Official statistics
The police record the number and type of crimes reported and the data is released annually by the government
Weakness:
They are unreliable and underestimate the extent of the crime. Criminologists suggest there is a ‘dark figure’ of crime which is responsible for 75% but not reported
Victim surveys
Involves questionnaires which ask if they have had a crime committed against them and if they deported it
Weakness:
Adversely affected by telescoping
Offender surveys
Involve self report of offenders enclosing the number and types of crimes they have committed
Weakness:
Due to the targeted nature, it tends to ignore “white collar crime”
Offender profiling
Enables investigators to predict characteristics of unknown criminal
Top-Down Approach
Starts with an establish typology and uses crime scene evidence to assign them to an organised or disorganised offender The 7 decision making tools: Murder type Primary intent Victim risk Offender risk Escalation Time Location
Organised offender
- Targets victim in a planned manner
- Higher than average intelligence
- Socially and sexually competent
Disorganised offender
- Little planning and leaves clues
- Lower than average intelligence
- Socially and sexually incompetent
Weaknesses of top-down approach
- Can only be used on crimes such as murder and rape
- Alison et al said it is naive to believe that behaviour is caused by stable disposition so personality traits
- Canter et al found no evidence for it when using 39 characteristics of a killer
Strength of top-down approach
Canter did fine distinctive evidence for an organised killer which is still used by US profilers
Bottom-up approach
Looks at crime scene evidence to develop a hypothesis about the characteristics motivations and social background of the offender
Investigative psychology
A type of bottoms up approach
- It uses crime scene evidence
- With psychological theory
- Based on statistical analysis
- Of typical offender behaviour patterns
The aim is to establish patterns of behaviour that are likely to occur across crime scenes to help determine if the crime has been committed by the same person
Geographical Profiling
Based on spatial consistency
The geographical locations of the previous crimes reveals their operational base and possible locations for future offences
Evaluation of Bottom-Up
Can be applied to more crimes
CANTER AND HERITAGE
Found that the smallest space analysis allows them to establish whether more crimes done by sane person
HOWEVER
Rachel Nickells assailant ruled out for being too tall
