Archive for the 'Body Language' Category

22
Jun
05

“Livor Mortis�

Livor mortis refers to the presentation of blood as it has settled in the body. Depending on the presence and state of livor during the external exam, it may be useful for establishing two key elements of the investigation—postmortem interval and whether or not the body has been moved recently.

As soon as a person dies, blood essentially “reacts� to the pull of gravity and begins to collect in the lower parts of the body. Eventually the blood becomes stagnant and seeps into the areas of soft tissue that creates a purplish discoloration in the skin. This discoloration can appear as small blotches at first and can develop into larger areas in just a few hours. If a person is lying on their back in bed, then they should have posterior livor. If a person is lying face down on the floor, then they should have anterior livor. If a person is lying on their side, then they should have lateral livor.

I use the phrase “should have� in each example because of livor’s significance as to whether or not the body has been moved. Let’s say I work a scene where an elderly woman is found dead by her husband in the bedroom floor a few hours after going to take a nap. I can expect that any livor patterns present should be on whichever side of her body was against the floor. As soon as I enter the room, I attempt to evaluate livor with regard to position if at all possible. The individual may be clothed or there may not be any livor as it usually takes an hour or two before it is noticeable. My hope is that I recognize the body has been disturbed before I actually handle it to evaluate time of death. If it appears that any staging may have occurred, then there is a possibility of foul play. At the very least, evidence of the body being moved is cause for more questions before I proceed.

Let’s also say that the woman is face up on the floor and that her livor pattern is on the side of her body facing the ceiling. In most cases, the body has simply been rolled over and checked for vitals by paramedics. Questioning the officers present or the paramedics themselves addresses this issue. If first responders deny rolling the body over, then the husband has some explaining to do. Handling the body—or denying that he handled the body—doesn’t necessarily indicate foul play. Further questioning of the husband may reveal that he simply found his wife nude on the floor and wanted to clothe her before the ambulance arrived.

As long as the presentation of the livor is consistent with the position that the deceased was found in, then I proceed with the external examination. It is at this point that I can use livor to evaluate the approximate time of death by examining the areas of purplish discoloration. Depending on the manifestation of livor—small blotches versus larger areas—the person has likely been dead anywhere from 2-8 hours provided the livor has not become permanent or “fixed.� If the livor is fixed, then the person has likely been dead longer than 8 hours.

Determining fixation is not unlike determining the severity of a sunburn. Most people have pressed on an area of sunburned skin and noticed the color change that takes place when the finger is removed and the sunburn returns. Livor reacts the same way prior to becoming fixed. As long as the livor disappears momentarily or “blanches,� then it can be estimated that the death occurred between 2-8 hours prior. How quickly or how slowly the purplish discoloration returns will determine how close the livor is to becoming fixed. For the sake of “accuracy,� I like to evaluate more than one area and average the results as livor in different areas of the body can react differently.

Once the livor has become fixed, it will not shift with a change in body position. A person with fixed anterior livor will continue to have anterior livor even after being rolled onto their back. A person with anterior livor of just a few hours may have posterior livor by the time they spend the night on a morgue tray as their livor is still fluid and still affected by gravity.

There is another presentation of skin discoloration that should also be mentioned here, although it is much less common. Ingestion of certain substances can lead to an apparent livor pattern that is more red or cherry-pink than it is purple. This reddish discoloration may suggest ingestion of carbon monoxide, fluoride, or cyanide. The source of this discoloration has to do with how these substances affect the hemoglobin in the body. Many carbon monoxide or “CO� deaths where the person has committed suicide using vehicle exhaust fumes exhibit this kind of discoloration. Whereas the location of positional livor is affected by the orientation of the body, “toxic� livor can be seen in all surfaces of the skin regardless of body position.

Livor mortis should never be used as an exclusive means for establishing postmortem interval. In most cases, the onset of livor should be early enough that core temperature and the onset of rigor can be used to support the livor estimate.

10
Jun
05

“Algor Mortis�

Algor mortis refers to the rate at which a body cools after death. This rate of cooling makes it possible to determine the approximate time of death by counting backwards the number of hours the body appears to have cooled from the time that the temperature was taken. The preferred time window for evaluating algor mortis is within the first several hours after death. Beyond that, the rate of cooling becomes less and less accurate as the body temperature approaches equilibrium with that of its environment.

The rate of cooling of the body and its significance should be evaluated carefully because the body temperature is easily affected by the physiology of the individual (age, weight, illness,) and the conditions of the environment (temperature, clothing, surface, activity prior to death). Unless any of these conditions are outstanding, a body cools very little during the first hour postmortem. After the first hour to a period of about six hours postmortem, a body will generally cool at the rate of 1.5° Fahrenheit for each hour after death. Under normal conditions, a temperature of 95.6° indicates the body has cooled 3° from normal (98.6°) and has likely been dead 2-3 hours.

The most accurate means for taking body temperature on a deceased individual is internally.
Hospitals will usually be able to provide a rectal temperature on request, if they have not done so already. At a scene, it is usually easier—and much more desirable—to take a liver temperature. This reading is accomplished by inserting a meat thermometer into the body just under the rib cage on the right side at a slightly upward angle in order to ensure the end of the thermometer penetrates the liver. After a period of about five minutes, the thermometer “bottoms out� or stops decreasing. I usually start off my external examination by inserting the thermometer, and by the time my examination is complete, the reading is complete.

Temperatures can also increase due to physiology or environment. Someone who dies with a high fever has a higher plateau from which to cool and will subsequently give a higher reading. Someone who dies in a heated bedroom will cool more slowly than someone in an unheated garage.

I recall taking a liver temperature on a man that was dead in his backyard on a hot summer day. He was directly on the ground face up and the temperature was in the 90’s with a much higher heat index. By the time I had finished the external examination, the thermometer read 100° Fahrenheit. I’ve seen even higher temperature readings, but I attributed most of those to the thermometer being in direct sunlight with the convex bezel on the end acting as a magnifying glass.

Typically the main significance of algor mortis is when the estimated result is distinctly different from the suspected timeline of the death. An example would be if a husband claimed that his wife was alive less than an hour before calling 911, but the rate of cooling in normal conditions indicated that she had been dead at least three hours. He may have simply been mistaken due to his grief, or he may have spent some time removing evidence of illicit drug use. Further questioning of the husband will ordinarily provide a reason for the disparity once he has been presented with physical evidence that conflicts with his original story.

In most cases, a person has been dead for so long that the body temperature may be so low as to be irrelevant. Fortunately for the investigator other physical observations can be made to help establish the window of death when body cooling cannot.

06
Jun
05

“Postmortem Interval�

I’ve received a few emails and comments asking me to explain some of the terms I have used in recent posts. From now on, I’ll try to do a better of job of providing definitions as I use some of the more “technical� terms pertaining to death investigation. I plan on placing any posts that focus specifically on definitions in a new category titled “Body Language� so they can be found easier.

My last post referred to human decomposition and its role in measuring postmortem interval, which is essentially an estimation as to how much time has transpired from the time the person died to the time that it was examined. This estimation is approximate at best, and the accuracy is determined by the number of physiological changes that can be factored into the estimation as well as observations made at the scene of the death. These factors are variable and count on the investigator to rely on past experience in order to offer accurate opinions.

The three most common physiological changes for establishing postmortem interval are algor mortis, livor mortis, and rigor mortis. Algor mortis refers to the rate at which a body cools after death. Livor mortis refers to the presentation of blood as it has settled in the body. Rigor mortis refers to the postmortem stiffening of muscles. Each of these terms will be covered in more detail in subsequent posts.

These changes are easily altered by the conditions of the scene and the dynamics of the body. As such, the progression of these changes can vary greatly from case to case. It is also easier to make accurate calculations on a recent death than on one where a longer postmortem interval is apparent.

Scene conditions are basically observations made at the scene by the investigator. What was the state of dress of the individual? Were they dressed for bed or to go out in public? When was the last time that the mail was checked or the last time the newspaper was brought in? Did the most recent meal appear to be breakfast or dinner? All of these observations help to establish a timeline for the death itself.

Regardless of how many physiological or scene factors exist, the estimation of postmortem interval is just that—an estimation. Television makes it appear as though an investigator can determine time of death much more accurately than is possible in real life. It would be a gross misrepresentation of knowledge for someone to actually state unequivocally—as is often done on T.V.—that a death occurred at a certain time based on almost immediate observations. The only real accurate time of death is when medical personnel are present at the death or when a traumatic death is instantaneous and witnessed by another individual.

A more accurate way to label estimations of postmortem interval is to refer to the final determination as a “Window of Death� or “Window of Time� in which the death most likely occurred. At its most accurate, this window may be as broad as a few hours. Again, the longer the person appears to have been dead, then the longer the “Window of Death� is going to be.

Still, the time of death issue is second only to the cause of death issue when it comes to questions posed to the death investigator. In most cases, the agency investigating the circumstances of the death will present the death investigator with a scenario that they believe occurred and asked whether or not the presentation of physiological changes observed by the investigator match the suspected time line of events. At best, the death investigator is only able to state whether or not the observed changes are consistent or inconsistent with the time line.