what is lividity?

Lividity is the reddish to bluish-purple discoloration of the skin that occurs after death due to the settling and pooling of blood in the lower, dependent parts of the body. This happens because the heart stops pumping, causing blood to pool under the influence of gravity, leading to a characteristic skin color change known as livor mortis. Lividity usually begins within 30 minutes to 4 hours after death, becomes most pronounced around 12 hours, and eventually becomes fixed, indicating that the blood has settled and the discoloration won't change if the body's position is moved. The presence and pattern of lividity can help forensic investigators determine the time and circumstances of death, such as whether a body was moved postmortem.