Thermal imaging is an incredibly valuable and simple tool for patrol officers and detectives to employ when investigating allegations of strangulation assault cases and homicides. A thermal imaging device scans the infrared light emitted by everything in view to create a very detailed temperature pattern called a thermogram. The result is an image of heat that the naked eye cannot detect.
For the purposes of this discussion, the value of using such a device can be summed up by looking at two images. One is a standard photograph of an assault victim who appears to have no bruising around her neck. However, in the thermal image of her neck we can clearly see the thermal "shadow" of fingers wrapped around the victim's throat.
Police departments can purchase relatively inexpensive thermal imaging cameras for around $1,000 that produce very nice "photos" to be used as evidence. Often used in other professions such as HVAC repair, construction, engineering, and firefighting, these devices are very well-suited for police needs, as well. If you're able to purchase or borrow them, more advanced thermal imaging cameras with additional features will of course also work well for this purpose.
Having served as a police chief for a small city (Smithville, TX), I am keenly aware of the issues officers face with tight city budgets. Some departments simply cannot afford to spend even a thousand dollars on a thermal camera. My experience and service as a volunteer firefighter comes into play here. Guess what almost every fire department and volunteer fire department carries in their engine? A thermal imaging camera (TIC). Yes, most fire departments—even small rural agencies—have them on hand. Officers in small departments who have no access to thermal imaging cameras of their own may want to reach out to their firefighter brothers and sisters and ask them if they could borrow their TIC.
You could even use the fire department TIC to view images of a strangulation victim's neck and document that image by simply taking a picture of it with your smart phone. This would be admissible in court to help make a felony case out of what might otherwise appear to just be a Class C Misdemeanor Assault by Contact case.
Officers who would like to increase their knowledge of strangulation investigation training can go to this website provided by the Strangulation Training Institute:
I also highly recommend reading Officer Brian Bennett's articles on thermal imaging: "Subtle Signs of a Killer" and "Beneath the Surface." These two well-written pieces delve into the history of thermal imaging and the many ways it can be applied to criminal investigations.
I urge you to think "outside the box" and employ thermal imaging in your patrol and CID investigations. There is an extremely high likelihood that a perpetrator who strangles his or her partner but does not kill him or her will end up killing the victim in the future. In Texas and many other states, strangulation assault is now classified as a felony due to the danger and possibility of victims suffering serious brain damage from restriction of their air supply and arterial blood supply to the brain. If you can use thermal imaging to provide valuable evidence of such a crime having occurred, you could help prevent a murder.
Judge Kevin R. Madison is a former police chief, deputy sheriff, and assistant district attorney. He currently serves as the presiding judge for the Lakeway (TX) Municipal Court of Record and assists Texas Highway Patrol, Texas Games Wardens, and other law enforcement agencies who need emergency search and arrest warrants. He has over 12 years of experience as a certified volunteer firefighter/EMT.