Crime scripts and script clashes

Crime scripts

Crime scripts (Cornish 1994a, b) describe crimes, not as single ‘brick-through-the-window’ events, but as procedures, which may be more or less complex and branching, and involve different people playing different crime roles. Crime prevention interventions may be targeted at particular ‘pinch points’ in the procedure, for maximum effectiveness and implementability.

According to Cornish an early publication on interviewing offenders for preventive intelligence (Ekblom 1991), which set out a procedure for doing robbery on the Underground, was one source of inspiration for what has become a very productive line of thinking.

Scripts and the Conjunction of Criminal Opportunity

The Conjunction of Criminal Opportunity Framework (CCO) was originally conceived as a static, ‘anatomical’ depiction of the causal elements that had to come together for a criminal event to occur. Subsequently, a more dynamic approach tried to represent how the elements came together, whether by social structural factors or offenders foraging for opportunities.

The diagram below represents scripts, in terms of multiple scenes and steps in the commission of a crime such as car theft, where tools and false documents have to be procured, a suitable car spotted, taken, and then sold. Each scene can be characterised by its own necessary causal conditions, whether a given preparatory act is in itself illegal or not. Interventions can be considered for blocking each causal ‘ray’ at each step.

Scripts relate to the CCO Framework in additional ways. One of the causal elements of the conjunction is ‘resources for committing crime‘. A repertoire of scripts is one such resource (Ekblom and Tilley 2000). And it was realised that the other roles in CCO – preventers and promoters – can have scripts too – an idea taken forward in the concept of script clashes, in the last section on this page.

A wider view of crimes as complex systems was developed in the form of the Crime Role Grid. Every cell of the Grid represents a combination of crime x civil roles (e.g. offender x waste carrier), and each agent within this cell can be characterised in terms of the scripts they may have acquired/applied in pursuit of their goals (for example, the waste carrier+offender may have developed a script for convincing the waste holder that they have a licence for legal operation).

Revisiting the script concept

Ekblom and Gill (2016) attempted to consolidate the concept of scripts. To quote the abstract:

‘The use of Cornish’s crime-scripts approach in situational crime prevention grows apace. However, we believe the conceptual foundation of cognitive scripts imported from Abelson and colleagues was rather unclear and is too narrow to support current script research. We therefore review the notion of scripts to both promote clarity and better connect it to mainstream situational prevention and criminology more generally. We also seek to broaden the approach by exploring additional cross-disciplinary links. We believe all this will support the progressively more demanding uses to which the procedural analysis of crime may be put in research and practice and—more broadly—challenge how human behaviour in crime is analysed.’

Dehghanniri and Borrion (2021) offer a systematic review of scripts.

Scripts in toolkits

Scripts can play a central role in toolkits designed to help security users to understand, and counter, complex crimes, as set out below:

Hostile reconnaissance toolkit

In the development of the Hostile Reconnaissance toolkit, the idea emerged of of a generic ‘script x location x aims‘ approach. The backbone of the script was simply the sequence of movements the perpetrator takes when offsite, then approaching, entering, acting inside, and leaving each operational zone of the site (termed a scenario). At each position relative to a zone, the users were asked to consider the aims/goals of the perpetrator under the headings Strategy, Tactics, Observation and Avoidance.

The image below is of a page from the toolkit, that takes the user through selecting one such perpetrator position for the zone of interest:

Having picked a location and relative movement (e.g. entering the ticket hall), users were then asked to put themselves in the perpetrator’s shoes and consider what questions they might ask themselves about the site, and the actions they might seek to take there.

See more details on the Hostile reconnaissance toolkit.

Terrorism/crime at complex stations toolkit

In this toolkit, drawing on databases of attacks and criminal Modus Operandi, the team developed a ‘conceptual attack framework’ which enabled analysis of attack methods (e.g. marauding), weapons (e.g. knives, guns), targets (e.g. passengers, infrastructure) and procedures – that is, scripts. A particular notation was developed to represent the scripts. (Note: ‘hygiene’ goals are things the perpetrator wants to avoid, e.g. getting prematurely discovered.)

The diagram below shows a partially-collapsed version of the attack procedure, used in developing the final toolkit:

Working through the toolkit (see slide below) leads users to the ‘think perpetrator’ stage (in pink). They select an offence type to focus on (e.g. terrorism, robbery, pickpocketing), then an attack method (e.g. terrorism-hostile vehicle ramming). Then, for a prespecified zone within the station, they consider from a menu which actions the perpetrator might take in support of that attack method (i.e. their attack procedure/ script). Then (switching from ‘think perpetrator’ to ‘think environment’ – in yellow) the users consider a menu of risk attributes of the target and the zone which might motivate, facilitate or be exploited by the perpetrator in support of their attack method.

The image below is a screenshot of the toolkit, guiding users to analyse and record the attack procedure/ script of the perpetrator in a particular zone of their station, for the attack method of terrorism-hostile vehicle ramming. The script steps shown in the dropdown boxes have been predetermined by the toolkit designers – ‘approaching the zone’ is shown here – but there is room for incorporating local information in the free text fields:

See more details on the Terrorism/ crime at complex stations toolkit.

Script clashes – a challenge for designers, technologists and engineers

Tactical script clashes occur between players of adversarial crime roles – especially offender vs preventer or responder, as discussed in Ekblom and Gill (2016). There seem to be just a few archetypical clashes, such as ‘confront vs avoid’.

It is the designer’s task to arrange the environment, products, services etc such that the balance favours the good guys:

The more clearly the contradictions are stated, the more helpful it is for the designer.

Of course, new technology, social change etc can tip the balance back the other way, to advantage offenders, so designers, engineers and technologists have to keep up – and for this they need to adopt an anticipatory approach, or at least to receive regular updates from police and other sources about the latest Modus Operandi and countermeasures by criminals/ security.

The slide below lists typical script clashes:

The above slide refers to TRIZ – this is a ‘theory of inventive principles’ which is discussed in Ekblom (2012g).