Week 5 Flashcards
What is investigative psychology?
A field of applied psychology developed by David Canter to make police psychology and investigation more scientific and academically rigorous instead of subjective
Who is David Canter? (3)
Father of IP
Background as an environmental psychologist, looking at how space impacts our behavior
Got involved in policing when the police reached out to him for his environmental work during the Railway Rapist investigation
He created a geographic profile that assisted in finding the offender and started the field
What are the core features of IP? (4)
A scientific approach to assisting police
Utilizes research methods to handle police data
Attempts to understand both offenders and police
Develop practical strategies beyond inference and guess based prediction
What are some of the applications of IP? (6)
Linking serial crimes
Crime scene analysis (criminal profiling)
Geographic profiling
Truth verification
Hostage negotiation
Suicide note veracity
What is crime linkage analysis? (2)
Reliance on behavioral evidence since physical evidence is often not available
Techniques that rely on behaviors to link crimes is behavioral crime linkage analysis
Why is crime linkage important? (2)
Allows you to pool evidence and resources, creating a greater likelihood of solving crimes
Allows you to obtain more sever sentences for more offenses linked to one offender
What are the 2 different types of crime linkage scenarios? What are examples of each?
Comparative case analysis, where large samples of crimes are searched by a practitioner for potential linkages
A practitioner is given an index crime that they think isn’t a one off so they search a database for other behaviorally similar crimes
Crime linkage analysis, where limited crimes are brought to a practitioner who needs to determine whether the crimes are linked
A practitioner is presented with a pre-defined set of crimes and they must determine whether they are linked
What are the 2 assumptions underlying all linking tasks? Which assumption receives more focus?
Behavioral stability (to some degree, offenders will display similar behaviors across their crimes or there would be no reason to believe they could all be linked)
Behavioral distinctiveness (to some degree, offenders committing similar crimes will commit those crimes in a distinctive fashion so they cannot all be linked)
Detectives use stability more, which is why they are so bad because if there is no distinctiveness for a crime (B&E through a window, which is most), crimes will be linked without actually being done by the same offender
What is the main theory behind crime linkage? What does it examine? What is the problem with this?
Personality psychology
Examines behavioral consistency and how people consistently exhibit individual behavioral differences over situations due to internal predispositions and traits we possess
Traits are not the primary determinant of behavior but different situational factors can make us change how we act (how the victim acts)
What is CAPS and how does it relate to crime linkage? (5)
Cognitive-affective personality systems
Assumes that personality traits and situational factors influence our behavior, mediated by cognitive (thoughts) and affect (feelings)
Behavioral strategies are activated by internal triggers (traits, fantasy) and external triggers (victim, environment) across crimes
Strategies will be consistent because the same strategies are activated across similar situations (especially if the strategies work to commit the crime successfully)
Distinctiveness in strategies results from the fact that offenders understand/process information/situations differently based on learning theory
What are 4 linkage approaches?
Modus operandi based procedures
Behavioral signatures
Linkage databases (MO and signatures)
Linkage as diagnosis (MO based procedures)
What is modus operandi? (3) What is the challenge?
The method used by an offender to successfully commit a crime and get away with it
It is the oldest approach used to like serial crimes
Assumes offenders will exhibit the same behaviors each time they commit their crimes
An MO is not always stable, offenders change behaviors for a variety of reasons (situational factors, maturation)
What are behavioral signatures? (3) what are the challenges? (2)
Behaviors that are exhibited, not because they are necessary for crime commission, but because they satisfy some psychological/emotional need
Not necessary, more unique and for a reason other than committing the crime
It could even impede the ability to get away with the crime
Limited empirical research on behavioral signatures in terms of definition and recognition
Still susceptible to environmental factors
What are linkage databases? (5) what are the challenges? (3)
Databases like ViCLAS (RCMP) and ViCAP were developed to reduce linkage blindness
They capture information related to crimes committed across jurisdictions
Specially trained analyst attempt to identify linkages bracket (in Canada, this is done at the Canadian police college)
This allows analysts to compare many crimes using range of searchable linkage indicators, with them completely in control over linking
Allows for a more human subjective analysis, rather than a rigid AI based one that cannot pick up on human differences and behavior
Lack of research on data, reliability and accuracy, consistency and distinctiveness of MO and signatures is not defined, and the ability of analyst to identified potential linkages is inconsistent based on the analyst
What is linkage as a diagnosis task? (3) What are the outcomes? (4)
Treats linkage diagnostic tasks as we do every other diagnostic task so we can compare them to other studies on similar tasks, which use the same framework as there’s been a lot of research on those tasks (cancer, weather)
Views linkage as a two alternative yes- no diagnostic task to discriminate between linked and unlinked crimes using evidence
The goal of every diagnostic task is to maximize the correct responses and minimize the wrong responses
Hit (true positive where it was predicted to be linked, and it was the same offender)
Miss (false negative where it was predicted to be unlinked, but it was the same offender)
False alarm (false positive where it was predicted to be linked, but it was different offenders)
Correct rejection (true negative where it was predicted to be unlinked, and it was different offenders)
What is the best evidence for crime linkage?
Unambiguous (occurs only for linked crimes or unlinked crimes)
Accurately and reliably coded