What does post-mortem lividity indicate about a body?

Post-mortem lividity, also known as hypostasis, refers to the settling of blood in the lowest parts of the body after death due to gravity. This phenomenon can help investigators determine whether a body has been moved after death. When a person dies, blood begins to pool in the areas of the body closest to the ground, leading to a discoloration of the skin.

If a body appears with lividity showing on surfaces that are not in contact with the ground, it indicates that the body was likely moved after the lividity had developed. Investigators can use this information to form conclusions about the circumstances surrounding the death and the possible movement of the body, which could be crucial in an investigation.

The other options deal with aspects that are not indicated by lividity. While it can provide some insight into time since death, it is not a definitive measure. Determining the exact cause of death or the identity of the victim would require additional evidence and is not directly related to lividity. Thus, the indication regarding movement is the primary significance of post-mortem lividity in forensic investigations.