AC1.2- Evaluate the usefulness of investigative techniques in criminal investigations
Profiling a murderer
Criminal profiling
Creating a portrait of the most likely perpetrator, based on evidence, such as the crime
scene.
Geographical profiling
Finding out the area in which the perpetrator is most likely located, based on locations of
past crimes.
Jack the Ripper- case study
As a result of geographical profiling, it was found that Jack the Ripper didn’t live in the
location he killed in. therefore this case may have been solved if geographical profiling was
available.
The Railway Rapist- case study
John Duffy and David Mulchany were the offenders
Between 1975 and 1986, 23 women were raped aged between 15 and 32 at railway
stations in and around London
Canter (a famous profiler) placed all the cases on a map, which allowed him to
speculate where the rapist lived
Studying the cases over 4 years, they placed the cases on a map to reveal distinctive
patterns in the locations and types of crimes
Duffy was convicted in February 1988, for 2 murders and rapes
Mulchany was arrested in February 1999, as DNA test were not available during the
investigation, but later was able to prove his involvement
The circle theory
Assumes the offenders home is central to where the crimes take place
Criminal consistency theory- commits crimes in a consistent way
, Marauders commit crime around an area they live in
Commuters commit crimes in an area they are familiar with but don’t live in
Criminal and Offender Profiling
Offender profiling
Its possible to work out the characteristics of an offender by examining the
characteristics of their offence
Generate offenders by using evidence and crimes which match the characteristics
Strengths
Provides useful investigative information
Creates heightened level of victim protection
Weaknesses
Based on educated assumption only
Adds to a profile but is not fact based
Not 100% accurate
Based on consistency
Top-down approach
Offender profiles match what’s known about the crime and offender to a pre-existing
template
Occupation, education, age, IQ, ethnicity all help narrow suspects down
Use classification of crime scenes, organised/ disorganised
Originally based on an interview with 36 convicted serial killers, rapists and crimes
solved by the FBI
Definitions
Organised crime- attempts to control the victim, victim targeted, leaves few clues.
Organised murder- above average intelligence, manipulative, cunning, socially and
sexually competent, angry and depressed during outbreak.
Disorganised crime- spontaneous, evidence not hidden, leaves weapon.
Disorganised murder- lives alone near the scene, suffers with mental illness, possibly
physically/ sexually abused.
Investigative techniques surveillance
Profiling a murderer
Criminal profiling
Creating a portrait of the most likely perpetrator, based on evidence, such as the crime
scene.
Geographical profiling
Finding out the area in which the perpetrator is most likely located, based on locations of
past crimes.
Jack the Ripper- case study
As a result of geographical profiling, it was found that Jack the Ripper didn’t live in the
location he killed in. therefore this case may have been solved if geographical profiling was
available.
The Railway Rapist- case study
John Duffy and David Mulchany were the offenders
Between 1975 and 1986, 23 women were raped aged between 15 and 32 at railway
stations in and around London
Canter (a famous profiler) placed all the cases on a map, which allowed him to
speculate where the rapist lived
Studying the cases over 4 years, they placed the cases on a map to reveal distinctive
patterns in the locations and types of crimes
Duffy was convicted in February 1988, for 2 murders and rapes
Mulchany was arrested in February 1999, as DNA test were not available during the
investigation, but later was able to prove his involvement
The circle theory
Assumes the offenders home is central to where the crimes take place
Criminal consistency theory- commits crimes in a consistent way
, Marauders commit crime around an area they live in
Commuters commit crimes in an area they are familiar with but don’t live in
Criminal and Offender Profiling
Offender profiling
Its possible to work out the characteristics of an offender by examining the
characteristics of their offence
Generate offenders by using evidence and crimes which match the characteristics
Strengths
Provides useful investigative information
Creates heightened level of victim protection
Weaknesses
Based on educated assumption only
Adds to a profile but is not fact based
Not 100% accurate
Based on consistency
Top-down approach
Offender profiles match what’s known about the crime and offender to a pre-existing
template
Occupation, education, age, IQ, ethnicity all help narrow suspects down
Use classification of crime scenes, organised/ disorganised
Originally based on an interview with 36 convicted serial killers, rapists and crimes
solved by the FBI
Definitions
Organised crime- attempts to control the victim, victim targeted, leaves few clues.
Organised murder- above average intelligence, manipulative, cunning, socially and
sexually competent, angry and depressed during outbreak.
Disorganised crime- spontaneous, evidence not hidden, leaves weapon.
Disorganised murder- lives alone near the scene, suffers with mental illness, possibly
physically/ sexually abused.
Investigative techniques surveillance
