Have you ever watched Castle or Body of Proof? Remember when the medical examiner would determine the time of death with certainty but it turns out that the estimation isn’t as scientific or certain as it’s portrayed.
Investigators use the Time of Death Certainty Principle. If you know with certainty when the person was last known to be alive, and if you know with certainty when they were found dead, then you know with 100% certainty that they died within that interval.
Certain changes that occur in the body after death can help determine the time of death such as:
- Lividity: This is the process through which the body’s blood supply will stop moving after the heart has stopped pumping it and the blood supply remaining in the body settles in response to gravity and results in purple discolouration.
- Rigor Mortis: This is the natural process of the contraction and relaxation of the body’s muscles caused by changes in the body’s chemical balances. This is a good measuring stick for estimating the time of death.
Non medical factors also play their part. For example, the last text message the victim sent can determine when they were alive.
All these factors help establish a time frame within which death could have occurred but cannot determine the exact time.