Post mortem interval (PMI) is the time that has elapsed since a person has died. If the time in question is not known, a number of medical/scientific techniques are used to determine it.

Some of the methods used to determine PMI are as follows:

• Algor mortis - body cooling.
• Rigor mortis - stiffening of limbs.
• Vitreous humour changes - eye chemistry.
• Entomology - insect activity on the corpse.
• State of decomposition (autolysis and putrefaction).