marry theory

Marrying Your Theory

By: Joseph Giacalone

There is an old maxim, “Be careful who you date, you might end up marrying them.” The same line of thinking has a lot to do with theory building in homicide investigations. A theory or hypothesis on how the crime was committed is a usual course of behavior by detectives at a crime scene. After arriving on the scene, the case investigator and supervisor will gather the squad and talk about the event. From this Intel gathering session, theories are developed on what happened, why did it happen and who was responsible.

Investigators keep three (3) things in mind when developing a theory – MOM: Means, Opportunity and Motive. These three elements helps develop suspects and build your theory. The theory is used to develop questions for canvassing and provide a starting point when nothing else exists. For instance, a female victim is found in the doorway of her home with a bullet wound to the head. There is no video surveillance, ballistic evidence or anything else. One theory would be that this was a ‘for hire’ murder. In these types of instances a strong theory investigators would develop would be that her spouse had her murdered. Why? A killing in a doorway is often done by a stranger, inside the back bedroom, you would be thinking significant other.

Investigators create these theories so they could start asking family and friends about their relations before speaking to the spouse – or to be used as a launchpad for the investigation if no motive seems to exist. If everyone is telling you that the relationship was fine, no signs of abuse and everything seemed to be going well with the victim, then investigators may not have discovered the right motive.

The theory isn’t, “Think it and Prove It. The problem occurs when the investigator lets the theory run the investigation, even in the face of surmounting evidence that it is wrong. We all want to be right and solve the case, but let the evidence dictate the investigation. Investigators must admit when their theory is wrong and be able to change tactics and their mental state. The longer the change in mindset takes, the more time is wasted and your perpetrator is getting further away.