Chalk Outlines

In all but one of the crime scenes I've been to, evidence location was marked by flags or little signs, but I did see one homicide in London, Ontario in the mid-90s where there was a chalk outline of the body and marking other evidence locations. Using chalk at crime scenes is not recommended because it contaminates the area, but it might have been because it was in a busy location and the victim's body  needed to be removed to hospital. A STRAIGHT DOPE CLASSIC: Do crime scene investigators really draw a chalk line around the body?

I've cropped this! There was a lot of blood in the upper part of the photo.