How long after death does lividity usually begin to start?

Lividity, also known as hypostasis, refers to the pooling of blood in the dependent areas of the body after death due to gravity. This phenomenon typically begins within one to two hours post-mortem. During this time, the blood starts to settle in the lower parts of the body, leading to a noticeable discoloration of the skin.

The timing is significant as it aids forensic professionals in estimating the time of death, which is critical in investigations. Understanding the timeline of lividity can help differentiate between an accidental death and a homicide or other circumstances surrounding the death. This initial phase of lividity can provide essential information regarding the position of the body after death and any potential movement that may have occurred before the body was discovered.

The other timeframes mentioned—3 to 4 hours, 5 to 6 hours, and 12 hours—while they may pertain more to the extent or settling of lividity or other post-mortem changes, do not accurately reflect when lividity first starts to become visible. Hence, the answer indicating one to two hours is aligned with established forensic understanding and offers an important benchmark in post-mortem examinations.