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Geographic Profiling. A Component of Criminal Profiling CRIM B55. Geographic Profiling: Case Types. Serial Murder Serial Rape Arson Bank Robbery Burglary Kidnapping Bombings. Geo Profiling Elements. Complete familiarity w/case file Examination of C/Ss
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Geographic Profiling A Component of Criminal ProfilingCRIM B55
Geographic Profiling: Case Types • Serial Murder • Serial Rape • Arson • Bank Robbery • Burglary • Kidnapping • Bombings
Geo Profiling Elements • Complete familiarity w/case file • Examination of C/Ss • Interviews w/ investigators and Ws • Study of area maps • Analysis of neighborhood demographics: ---abduction site and body dump site • Computerized analysis
Geo Profiling Elements • Distance Perceptions (subjective)+ Actual • Mobility and Alternative routes (Plan B) • Familiarity with “route” + and – aspects • Number and Types of barriers: natural, structural, jurisdictional, psychological • Mental Maps (S “image” of the city) • Locality demographics: Age, Race, SES, • Land Use: Zoning, topography, etc.
Geo Pro: Underlying Principles • Valid linkage analysis to determine that a set of crime sites belong to the same series (S,V, C/S inputs) • Valid geographic modeling of the travel distance to crime sites for a particular type of crime, criminal, and geographic area (Computer programs)
Computer Models in Geo Pro • Rigel—Professor K. Rossmo (Texas State U at San Marcos) + ECRI • VICLAS--RCMP • VICAP--FBI • Predator—Professor Maurice Godwin • HALT—NYSP • HITS- Washington State AG
Investigative Questions to Consider • Locations • What are the location types connected to this crime or crime series? • Where are these locations? Map them! • What are the distances and travel times between them?
Investigative Questions to Consider • Time • When did the crimes occur (date, time, weekday)? • What was the weather? • How much time was there between crimes?
Investigative Questions to Consider • Site Selection • How are the crime locations accessed? • What else is in the general area? • How might the offender have known of these locations? • What purpose did the crime locations serve?
Investigative Questions to Consider • Target Backcloth • Where is the target group (and where is it not)? • How much control did the offender have over the choice of crime locations? • Has displacement (in space or time) occurred?
Hunting What hunting method did the offender use? Why these sites and not others? What was the offender's likely transportation? Investigative Questions to Consider
Investigative Strategies and Geo Pro Applications • Prioritizing S list • Prioritizing Tips list • Address searches: databases (zip codes) • Patrol saturation (selective enforcement) • Surveillances • Canvasses and searches • DNA searches
Known movement patterns Comfort zones Hunting patterns R handed S flee left; discard W right Lost Male S go downhill Lost Female S go uphill Need at least 5 crimes or C/Ss to make it work—must be clearly linked CGT Considerations (Rossmo)
Encounter Sites: Godwin Model • Urban subcultures (bars, night clubs, and red light areas) • Isolated landscapes (parking lots, jogging paths, and rest areas) • Areas with a high concentration of elderly and poor individuals • Derelict areas of a city • University campuses
Crime Locations** for Geo Pro • Encounter Site • Attack Site • Crime Site • Victim Disposal Site • Vehicle Dump Site **Importance of Displacement ** Analysis used in murder and rape cases
Offender Styles: Target Selection • Hunter (searches for a specific victim in home territory) • Poacher (travels away from home for hunting) • Troller (opportunistic encounters while occupied in other activities) • Trapper (creates a situation to draw a victim to him)
CGT Method (ECRI + Rigel) • Spatial characteristics of crime assessed • Topographical map produced (similar crimes) • Graphing of jeopardy surface • Superimposition on street map • Crimes pinpointed (old pin maps!) • “Fingerprints” of S cognitive map • > # of C/Ss > predictive value
Hit Score Calculation • Hit Score: The value (z-score) associated with the location of an offender’s residence or anchor point. • Hit Score Percentage: An indicator of search efficiency used in geographic profiling, measured by determining the proportion of the total hunting area covered before the offender’s residence is encountered. The smaller the number, the better the focus of the geographic profile.
Hit Score Percentages • Describes Optimal Search Process • Starts at most probable area outward • Measures proportion of hunting area covered before locating S residence • Search area=locations covered • Smaller number=better geo profile focus • Ex: 70 cases (See: Inv. Trainor’s cases)
Relationship to Criminal Profiling • Psychological Motivation • Organized/Disorganized Behavior • Offender Lifestyle demographics • Target Selection and Victim Risk • Integration w/ CGT (Criminal Geographic Targeting)
