From Scott:

Last time, our discussion on death scenes included suicides, accidental deaths, and natural deaths. In this week’s blog, we’ll take a look at questionable deaths and homicide scenes.

The questionable death scene is a difficult one. Often, there are no obvious signs of trauma on the body and no obvious mechanism of death. It might even be unclear how the body came to be where it is. These cases are treated as homicides until we find sufficient evidence to decide otherwise.

Take for example the male body we found along the Illinois River a few years ago, just before Christmas. His body showed no signs of injury. Although the river had not yet frozen over, his clothing was dry, making it unlikely that he had drowned. He was lying face down in the sand, missing a shoe and wearing a jacket that wasn’t heavy enough for the frigid temperatures. A short distance to the west of his body was a seven-foot-high concrete wall, built to keep the river away from nearby homes during floods.

Was he strangled? Did he drown and get washed up on the bank (unlikely, with his dry clothing)? Did he fall off the wall, become incapacitated and die of hypothermia? Or was he killed elsewhere and dumped by the river?

At the base of the wall, nearly hidden inside a thick thorn bush, I found the missing shoe. It would be our only real clue from the scene. The autopsy showed no injuries, aside from minor scratches (likely from the thorns). Examination of his organs showed none of the tissue damage associated with hypothermia. And the lividity (the purplish color on the skin, where blood has settled into the body’s lowest points) was consistent with the body’s position when we found him, so it didn’t appear he had died elsewhere and was later dumped by the river.

A thorough investigation followed. The end result was that the blood toxicology reports (or “tox” for short, in police lingo) showed that he died of a drug overdose. He had been at a party a block or so away. Based upon our investigation, it appeared that he wandered away from the house and fell off the wall. The drug overdose claimed his life before the cold temperatures.

You can see how these questionable scenes can leave investigators pulling their hair out. Nothing pointed at a homicide, yet we still treated it like one, just in case. We looked at the situation from every possible angle before concluding no foul play was involved.

Sometimes, a drug overdose can actually become a homicide case. Although difficult to prove, Drug-Induced Homicides (as the Illinois statutes refer to them) are, on occasion, prosecuted when evidence permits. The problem is that we have to show in court, beyond a reasonable doubt, that the drugs the deceased person bought from the suspect are the drugs that caused the overdose. Even as I type these words, this situation brings up the beginnings of a mystery plot: the detective investigates the drug dealer to prove drug-induced homicide, but stumbles upon something much more sinister.

The last type of death scene we’ll look at is the homicide. More often than not, homicide scenes are quite obviously not a natural death or a suicide. The first officers on the scene (usually patrol officers, not investigators) will secure the area, not just to preserve the evidence, but to ensure that the suspect isn’t still there. A crime scene investigator, head-down over a case, would be easy prey for the killer!

In Part Two of this series, I discussed the procedures at a homicide scene. Rather than go into great detail again, I’ll spare you the redundancy and give an overview. The crime scene investigator walks through the scene first, to get an idea of what’s involved. Next come photography and videography, in order to document and preserve the scene as it was at the time it was discovered. Measurements are taken to all major items of interest, which will later be used to create a scale diagram. Once all of this is done, the body and other evidence can be removed.

The scene is protected by placing yellow crime scene tape around the perimeter. We deliberately make the perimeter larger than needed. We can always shrink the area down later, but if we don’t go large enough, any evidence outside the tape may become tainted and would lose some of its evidentiary value in court. There is only one point in the perimeter that people are allowed to pass through. An officer stands there with a logbook, taking note of everyone who enters or exits, and at what time. Access should be limited to people who have a need to be inside the crime scene area, not curious officers who aren’t actually part of the investigation.

One of the messiest murder weapons we see is the knife. When the killer starts poking holes in the body, blood comes rushing out, sometimes in astonishing amounts. If an artery is severed, every beat of the heart shoots a fountain of blood out through the wound, producing a telltale blood pattern on the walls and floors. Once the victim dies, the blood pressure drops to zero. At that point, the bleeding will stop, unless one or more of the stab wounds are on the side of the body facing the ground. In that case, it’s no different than poking holes in a water jug. Until the water level drops below the holes, the water leaks out.

Another sign to look for in a stabbing is defensive wounds. The victim, in the process of fighting for life, will grab the knife blade, resulting in lacerations to the palms and fingers. The suspect typically receives cuts from the murder weapon as well. This is why the police in Los Angeles were so interested in the cuts on O.J. Simpsons’s hands. I’m making no claims as to his guilt or innocence; I’m only saying that the investigating officers were aware that if he killed the two victims, there was a good chance he would have cut himself in the process.

Firearms are another matter. If the bullet passes completely through the body, a fine mist of blood sprays out through the exit wound, producing a unique blood pattern. If the weapon’s action is semi-automatic, a spent shell casing will be ejected every time the weapon is fired. In the case of bolt action or pump action weapons, the casing is only ejected when another round is loaded. For revolvers, the only way casings are left at the scene is if the killer empties the cylinder, which would be fairly dumb (unless there was a pressing need to reload the weapon).

When a gun is pressed against the victim and fired, this is called a “contact wound.” Often, the impression of the muzzle of the weapon is visible on the victim’s skin. Gray gunpowder residue can be found inside the wound, and blood from the victim can sometimes be found inside the barrel of the gun. If the shot was fired from close range, say within a foot or so, the gunpowder residue will leave tiny burn marks on skin and clothing, called “stipling.”

Most murders are crimes of passion. As a result, we usually find a mountain of evidence at the scene, all pointing us in the direction of the killer. Occasionally, there are cases where the murder is planned out ahead of time, sometimes by a person who is cunning enough to minimize the chances of law enforcement discovering who committed the crime. This is usually the situation when a serial killer is involved. These predators, usually male, tend to plan their killings out in advance. Ten years ago, we had a serial killer active in our county. When he dumped a body, he took precautions. If the girl fought him, he scraped under her fingernails and soaked her hands in bleach to remove any possible DNA traces. He would also check the area to make sure he left behind no garbage and no footwear or tire mark evidence. But that sounds like the topic of a future blog installment!

This concludes the series on investigations of death scenes. In the future, I’ll go into other areas of police procedure, including evidence collection, fingerprint processing and identification, and of course the story of our most recent serial killer.

–Scott