What is rigor mortis and when does it typically begin?

Rigor mortis is a physiological process that occurs after death, characterized by the stiffening of the muscles due to biochemical changes within muscle tissue. This process is primarily caused by the depletion of ATP (adenosine triphosphate), which is necessary for muscle relaxation. When the body ceases to produce ATP, the muscles can no longer relax, resulting in a state of rigidity.

This stiffening typically begins within 2 to 6 hours after death, depending on various factors such as ambient temperature and the physical condition of the deceased. As time progresses, rigor mortis reaches its peak rigidity around 12 hours after death and eventually dissipates after 24 to 48 hours as the muscles start to decompose.

Understanding the timeline of rigor mortis is essential for forensic science, as it can assist in estimating the time of death, which is critical in both legal investigations and funeral practices.