Comparative Case Analysis

 The College of Policing, a professional body for everyone who works for the police service in England and Wales, has a webpage for Analytical Techniques that can be found at this link. 

One of my favorite techniques to use when I was working at the local level of law enforcement is defined from that website:

"Comparative case analysis

CCA allows a number of similar crimes or incidents to be identified as part of a series which are likely to have been committed by one offender or a group of offenders. They will be linked through similarities in:

modus operandi (MO)

signature behaviour

intelligence

forensic evidence.

CCA is usually carried out using a chart or table which allows the analyst to organise data in a format where descriptive details of the crime or incidents are displayed in one place. Details may include people, objects, locations, events, language used, MO and vehicles, which would then allow the analyst to identify any potential linked series. This method allows the analyst to find patterns in the detail of an incident and crime which are distinct enough that it separates them from others which are not likely to be part of the series."

When I engaged in tactical crime analysis at the local level of law enforcement, I used this technique without knowing I was using a named technique. Unfortunately there is no agreed-upon, systematic method to compare cases and analyze cases across the crime analysis world. For that, we suffer in establishing credibility - each analyst is inventing their own methods or often using no structured methods at all.

Because of that, many crime analysts cannot testify to an agreed-upon "how and why" we did our tactical analysis. A stated methodology that is professionally approved would help. It doesn't have to look academic, but it must be logical and work in reality. Standards matter in professions.

To learn more about comparative case analysis, read A Preliminary Examination of Crime Analysts' Views and Experiences of Comparative Case Analysis at this link.

The video below is from the National Crime Agency.