Behavior Evidence Profiling:
Evidence is first recognized, documented, collected and then processed, usually by identification teams, made up of crime scene investigators. The next step, usually done by detectives, is investigative work, which compiles all the evidence and asks the question “why.” Why is the body in that position? Why are the casings in the other room? Why was there no forced entry? This is the reconstruction phase of the process. It is not enough to have the evidence. The meaning must be decoded. It is in the reconstruction process where the final picture develops and the scene and the body start to tell their story.
Patterns are important on all phases of the investigation but a medical legal investigator is mainly concerned with those wounds on or about the body. Sometimes the absence of certain types of wounds tell you as much as their presence. In the Ewalt case it was the absence of defense wounds and the lethalness of her two wounds that told me this was most likely an experienced killer. Her wound patterns were not consistent with most domestic or passion killings. The pattern wounds on the victim’s body many times tell the intent and purpose of the killer.
My work at the scene starts at the body and works outward towards the edges of the infamous yellow tape. I first look at body position because it is the beginning of the body speaking to me. Has it been moved? Was there a struggle? Was the death quick or agonizing? In Darlene’s case it was clear that the attack was sudden, from behind, and death was almost instantaneous.
Blood Pattern Analysis:
Blood has specific properties—one of those is surface tension. Because of this feature of blood, it can be analyzed mathematically as to origin and angle of impact. There are numerous types of patterns: transfer, low, medium and high velocity patterns, pooling patterns and arterial spurt patterns. The patterns at a scene and on the body can give information of movement at the scene, sequencing of the wounds, and how many persons were at the scene. Because of the importance of blood patterns, scene security and processing must be treated meticulously.