Jeopardy Surface
Definition
The probability map output of geographic profiling, rendered as a colour-coded topographic display where high-probability zones for the anchor point appear in red and low-probability zones in blue or green.
- Output format
- Colour-coded topographic display, with red indicating highest probability and blue/green indicating lowest.
- What it predicts
- The location of the anchor point (usually the offender's home, workplace, or base of operations).
- Core purpose
- To help investigators prioritize search areas by focusing on zones ranked most likely to contain the anchor point.
Common questions
What does a jeopardy surface actually show?+
A jeopardy surface is a probability map created by geographic profiling algorithms. It ranks every location in a search grid by how likely it is to contain the offender's anchor point (typically their home or base). High-probability zones appear in red, while low-probability zones show in blue or green, making hotspots easy to spot at a glance.
How do investigators use this map in the field?+
The color-coded heat-map shows police where to focus search efforts. Red zones indicate the most likely locations for the anchor point, so investigators can prioritize those areas. This helps narrow down a geographically dispersed offender pattern into actionable leads rather than searching blindly.
Is the jeopardy surface prediction always accurate?+
The jeopardy surface is a probabilistic tool, not a certainty. It works by analyzing the geographic distribution of an offender's crimes and applying mathematical models (like Rossmo's algorithm). The output is strongest when you have multiple crime locations to analyze. It narrows the search space and ranks areas by likelihood, but the actual anchor point can fall outside the highest-probability zones.
Related terms
- Buffer Zone
- The area immediately around an offender's anchor point where offence probability is suppressed because the offender avoids committing crimes near recognisable locations...
- Anchor Point
- The offender's spatial base of operations, most often the home, sometimes the workplace or a partner's address. The point geographical profiling is...
- Circle Hypothesis
- David Canter and Paul Larkin's 1993 hypothesis that for marauder offenders, the anchor point falls within the circle defined by the two...
- Commuter
- An offender who travels from their anchor point into a geographically separate crime area to offend; the circle hypothesis does not reliably...
- Criminal Geographic Targeting (CGT)
- Kim Rossmo's algorithm for geographic profiling, incorporating a distance-decay function modified by a buffer-zone suppression factor; implemented commercially in the Rigel software.
- Distance Decay
- The empirical observation that the probability of an offence location decreases as distance from the offender's anchor point increases, reflecting the rising...
- Distance-Decay Function
- The empirical pattern that offence frequency declines with distance from the offender's anchor point, after a small zone of avoidance close to...
- Geographic Profiling
- A spatial analysis technique originally developed by Kim Rossmo that predicts the likely home or anchor point of a serial offender from...
- Hit-Rate
- Performance metric for a geoprofile: the percentage of the search area that has to be examined before the anchor is found, lower...
- Marauder
- An offender who operates radially from a fixed anchor point, committing crimes within a radius around that point and returning to it...
- Rigel
- The commercial software implementing the CGT geographic profiling algorithm, developed by Environmental Criminology Research Inc. in Vancouver and licensed to law-enforcement agencies...
- Routine Activity Theory
- A criminological framework developed by Cohen and Felson (1979) that explains property crime as the product of three converging elements: a motivated...
Explained in these topics
- Geographic Profiling: Rossmo, Canter and the Jeopardy SurfaceThe probability map output of geographic profiling, rendered as a colour-coded topographic display where high-probability zones for the anchor point appear in...
- Geographical ProfilingThe probability heat-map output of a geoprofiling algorithm, ranking every cell in the search grid by likelihood of containing the anchor point.