![](https://primary.jwwb.nl/public/u/c/x/temp-nauhoageiwipozeczbjt/oip-5-standard.jpg)
When a person dies or is killed, the blood settles to the portion of the body closest to the ground. If a body has been moved post mortum, detectives can tell because they can see in the body where the blood has already settled. This is how they can tell if a certain location is the primary or secondary crime scene.