The time of death is as simple as it sounds – it is the time at which someone dies. Time of death is categorized into 3 different types:
- Physiological time of death: this is the time at which the person’s organs stop functioning and shut down.
- Estimated time of death: this is an educated guess on time of death based on any information available to investigators.
- Legal time of death: this is “time at which the body was discovered or physically pronounced dead by another individual” (“Estimating”). Legal time of death is the time that is entered on a death certificate.
One method of determining time of death is to take the temperature of the decedent. Investigators use a math equation to help decide how long the person has been dead. Temperature can be taken using a rectal thermometer or by measuring the temperature of the liver, which provides a more accurate core temperature. When taking temperature, the location the body was found in must be taken into account as well. If a body was found in the middle of winter in a lake, that will affect the temperature reading.
Rigor mortis can also help investigators determine the time of death. Rigor mortis is the “natural contracting and relaxation of the body’s muscles caused by changes in the body’s chemical balances” (“Estimating”). Rigor begins in the smaller muscles and works its way through the body. It begins soon after death and can last up to 30 hours after the person has died. It will leave the body eventually, so if a body is found and rigor is not present, it can be concluded that the decedent passed more than 30 hours previously.
For example, there was a man I took the fingerprints of my first week at my internship. Normally the elbow is bent so fingerprints are easier to take, but the man was still in rigor. Time of death had already been determined because there were witnesses to his death, but if it had been unknown, the rigor present in his body could have been a clue.
The insects found at a scene (as gross as it sounds) can also be used to estimate death. The insects present and how far along they are in their life cycle can provide insight to investigators.
When time of death is not known, investigators have a variety of ways to help them estimate the time of death. This can be valuable especially to death investigations when time of death can narrow down a suspect list.
Source: Claridge, Jack. “Estimating The Time of Death.” Explore Forensics. 21 Feb. 2016. Web. 19 Feb. 2016.