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.
This term refers to the rigidity of the muscles of the dead person. It is no accident that a common term for a dead person is “stiff”. Your muscles hold their tone and are able to contract and release through a complex chemical reaction of two molecules in the muscle cells: actin and myosin. Two chemicals, acetyl triphosphate and acetyl diphosphate allow this to happen. When a person dies the body is in a particular position. Left in that position for a period of time, the body will reach full rigor or stiffness. This happens because the two chemicals ATP and ADP are not going through their normal cycle. So rigor starts right away, it strengthens throughout the body and reaches full rigor in about six to eight hours. The rigor will leave the body in about twenty-four hours. Evaluating this helps provide a range for the time of death.
It is important to determine how far the muzzle of the gun was to the victim’s body at the time the weapon was discharged. The term sooting describes deposits of gunpowder residue on the skin of the victim. This burnt gunpowder can be washed or wiped off the body. Because it has little mass and would best be described as smoke residue, it can’t travel far from the barrel of the gun, so sooting is an indication of a close gunshot wound. Gunshot wounds are always described within a range. I define close range from near contact with the skin as approximately six to eight inches away from the target.
This is another term that relates to distance of the gun from the victim at the time of discharge. Stippling is partially burnt gunpowder residue. It has greater mass than the smoky, massless sooting residue and therefore can travel farther than soot. Once this unspent powder hits the victim’s skin it causes little red dots as it burns the epidermis, called “tattooing.” Booth sooting and tattooing can occur in a close rage shooting. If only stippling exists, then the gun was farther away. In my experience stippling occurs when the gun is eight inches to a little better than twelve inches away from target. All of these ranges depend upon the weapon and the ammunition used. Ranges can be reproduced with similar guns and ammunition to those in the incident by calibrating the distance from a whiteboard and then firing at multiple ranges.
A victimology is one of the keystones to deriving meaning from the evidence of an investigation. After the evidence is collected, documented and processed, the effort to give meaning to what all the evidence tells us is called “evidence reconstruction.” Evidence reconstruction begins with first studying the victim. This process is called building a victimology. The entire life is of importance, especially the last 48 hours before to death. In the first episode it readily became obvious that the victim knew the killer. There was passion involved in the assault. The victim was in the midst of trying to change her life as evidence of textbooks around the scene. A victimology must give meaning to why the victim was a victim.
Your DNA defines who you are uniquely. Most of your DNA is just like everybody else's but there are areas in the double helix that identify you more accurately than fingerprints. There is DNA in the nucleus of the cell, representing the profile of both the mother and father of the sample, and there is DNA from the engines of the cells, the mitochondria, representing only the maternal side of the sample. Each cell has many mitochondria, but only one nucleus. In most cases, mitochondrial DNA testing is done because a smaller sample is sufficient enough for identification.