bottom-up Flashcards
where does bottom-up originate from
Britain
how does the bottom-up approach work
makes use of past data on similar crimes to build a picture of the offender. doesn’t use fixed typologies like top-down, instead ‘data-driven’, with rigorous scrutiny of the offence details, more grounded in psychological theory
what’re the 2 main parts of your the bottom-up approach
investigative psychology
geographical profiling
what does investigative psychology involve
uses statistical procedures and psychological theory to analyse crime scene evidence, establishes behavioural patterns that may occur/co-exist across crime scenes (criminal characteristics). statistical database created for comparison with details of the offender (personal history, family background), may determine if crimes are linked.
what 3 components does investigative psychology consist of
interpersonal coherence
significance of time and place
forensic awareness
what is interpersonal coherence
offender behaviour at the scene, how they ‘interact’ with the victim eg control/humiliation or apologetic
what is the significance of time and place
may indicate where the offender lives
what is forensic awareness
shows individuals who have been in interrogation before, behaviour shows their mindfulness of ‘covering tracks’
what is geographical profiling
assumption that criminals’ work is restricted to geographical areas they’re familiar with understanding spatial pattern to build a ‘centre of gravity’ (likely to be offenders base). nah help with ‘jeopardy surface’
what is the ‘jeopardy surface’
educated guesses on offenders next likely actions/strike locations
what 3 aspects does geographical profiling consist of
spatial consistency
crime mapping
modus operandi
what is spatial consistency
people commit crimes in limited geographical spaces
what is crime mapping
uses location of linked crime scenes to make inferences about offenders’ likely home bases
what is modus operandi
particular way/method of doing something
what 2 offender behaviours does Carter & Larkin’s Circle theory consist of
the marauder
the commuter
what do marauders do (give example)
operate in close proximity to their home base (Dahmer)
what do commuters do (give example)
likely to travel distance from their usual residence (Bundy)
what does the Circle theory tell us
tells the nature of offence: planned or opportunistic, as well as other facts: employment status, transport mode used, occupation or approximate age etc
what’re 2 strengths of bottom-up approach
investigative psych supporting evidence
geographical profiling supporting evidence
what is a positive evaluation for investigative psychology in bottom-up
after analysing 66 SA cases, common behaviours such as ‘using impersonal language’/‘lack of reaction to victim’ emerged, helping establish case linkage supporting approach validity
what is case linkage
whether 2 or more offences are committed by the same persob
what is a positive evaluation of geographical profiling in top-down
collected info from 120 murder cases using smallest space analysis found spatial consistencies. each individual killer disposed of bodies in a different direction creating a ‘circle’ with home base at the centre. (more notable for marauders than commuters). shows real world application leading to higher crime solving rates.
what’re 2 negative evaluation points for bottom-up approach
mixed police results
significant failures
how do mixed police results negatively evaluate the bottom-up approach
in 48 police departments, profile advice was judged to be ‘useful’ in 83% of cases, but in only 3% of cases was the identification accurate. this suggests that there’s some use but other techniques are more important to catching criminals
what’s a significant failure of bottom-up approach
Rachel Nickell’s SA and stabbing 47 times led to a 5 month undercover investigation fake relationship with Colin Stagg to try get a confession. case was thrown out due to lack of evidence. real offender of Robert Napper was convicted but initially ruled out as he was several inches taller than profile. shows inaccuracies and over reliance can waste time and arrests, possible missing criminals
what’s the case of David Canter’s “Railway Rapist” John Duffy
assaulted women in London train stations 1982-85, leading to 3 women dying.
evidence showed more than one person was involved, Canter then helped, creating a profile of the offender with bottom-up.
suggested violent sexual history, poor past relationships, forensic awareness, mid-late 20’s and semi-skilled labourer.
Matched to John Duffy (separated, abusive history, criminal record with attempts to remove evidence and was a carpenter). Duffy also had worked for railways before.
Although not 100% accurate, the profile was sufficient for the police to interrogate/arrest Duffy. Duffy then gave up the name of his accomplice
