Terms, defined

Violence driven by a perceived threat: high physiological arousal, conscious anger or fear, reactive, quick, aimed at ending the threat.

Source: Meloy (2006) · Read: Cold and hot

The tendency of forensic experts to score the same evidence in the direction favoured by the side that retained them.

Source: Murrie et al. (2013) · Read: Forty points

Anyone or anything whose presence discourages an offence at the moment an offender meets a target: a passer-by, staff, a neighbour, a camera that someone watches.

Source: Cohen & Felson (1979) · Read: The walk

Interpreting unclear crime-scene evidence by reasoning backwards from the suspect's known material, so that the suspect's features are read into the evidence.

Source: Office of the Inspector General (2006) · Read: The print on the bag

Three overlapping but distinct personality traits measured in ordinary people: narcissism, Machiavellianism and psychopathy.

Source: Paulhus & Williams (2002) · Read: Forty points

A claim that could be shown wrong by the facts. In offender profiles, fewer than a third of claims meet this test.

Source: Alison et al. (2003) · Read: The profile and the common

How consistently a measure is scored by different people in real cases, as opposed to research conditions.

Source: Boccaccini et al. (2008) · Read: Forty points

The way context, such as knowing a suspect confessed, shapes how forensic examiners read ambiguous evidence.

Source: Kassin et al. (2013); Dror et al. (2006) · Read: The print on the bag

The process an offender uses to gain access to a child, win the trust of the child and the adults around them, and keep abuse secret. It works on three targets: the offender's own justifications, the environment and carers, and the child.

Source: Craven et al. (2006) · Read: The long approach

A killing that is premeditated, serves an external goal and is not preceded by a strong emotional reaction. The opposite of a reactive killing.

Source: Woodworth & Porter (2002) · Read: Cold and hot

How an offence is carried out: the concrete steps of access, approach, control and concealment, as opposed to why the offender wanted it.

Source: Leclerc et al. (2009) · Read: The long approach

A set of predictions about the unknown person who committed a crime, inferred from the crime.

Source: Snook et al. (2007) · Read: The profile and the common

The Hare Psychopathy Checklist–Revised: 20 items, each scored 0, 1 or 2 by a trained evaluator from interview and records, for a total of 0 to 40.

Source: Hare (2003); Hare (1980) · Read: Forty points

Violence that is planned or purposeful, with minimal arousal and no conscious emotion, focused on a chosen target, and not a response to an immediate threat.

Source: Meloy (2006); Meloy (1988) · Read: Cold and hot

A cluster of interpersonal, affective and behavioural traits: superficial charm, lack of remorse, shallow affect, callousness, impulsivity. A measure of it, such as the PCL-R, is not the same thing as the construct.

Source: Cleckley (1941); Skeem & Cooke (2010) · Read: Forty points

Being victimised again after a first offence, often soon after. A small share of victims and places carry a large share of crime.

Source: Farrell & Pease (1993) · Read: The walk

Direct-contact crime needs a likely offender and a suitable target to meet in time and space without a capable guardian.

Source: Cohen & Felson (1979) · Read: The walk

An investigation's focus on one suspect that leads it to seek, read and remember evidence in that suspect's favour and discount the rest. A product of ordinary cognition and institutional pressure.

Source: Findley & Scott (2006); O'Brien (2009) · Read: The print on the bag

The study of victims and victimisation: who is harmed, how events come together, and how to prevent the next one. Not the assignment of blame.

Source: von Hentig (1948); Farrell & Pease (1993) · Read: The walk