There are four "Manners of death"; homicide, suicide, accident, and natural. "Manner of death" is distinct from "Cause of death". Cause of death refers to such things as gunshot wound, heart attack, drowning, self-inflicted knife wound, etc. That is, the specific incident that effected the death. "Mechanism of death" refers to the internal bodily dysfunction that caused the death. For instance; if the "manner of death" was homicide, and the "cause of death" was a gunshot wound to the chest, then the "mechanism of death" might be a massive rupture wound to the heart, causing internal bleeding and asphyxia.
This section will briefly discuss the four manners of death in general, and how they affect the work of the law enforcement field officer in a death investigation.
HOMICIDE IN GENERAL
Homicide Investigation will be covered in a later chapter. This section is going to cover some general homicide statistics. An officer may have more confidence in his/her preliminary estimate of homicide as the manner of death, if his/her incident meets several of the following characteristics (the "profile"). But keep in mind that statistics are very limited as a profiling method.
Half of all homicides happen on weekends. Half happen between 8PM and 2AM. As American society becomes less structured, we can expect this statistic to continue to change; fewer murders will be happening during the traditional party hours.
Most murders happen in high crime areas, and most murders happen in the home. Alcohol and drug use are usually involved. Of weapons used in homicides, 65% are guns and 20% are knives. Women are more prone to use knives. Murders committed with premeditation or by men, more frequently are committed with guns. Passionate murders (sex motive, etc) are more frequently committed with knives.
80% of the victims and 80% of the killers are men. This is changing as women become more violent, and more involved in the dangerous activities of our society. Murder is predominately an intra-racial crime, and the incidence of murder is proportionately higher, both as to victim and killer, among minorities and among economically deprived (poorer) people.
25% of all murders happen within the immediate family. Three quarters of all homicide victims were killed by someone they knew.
The presence or absence of any or all of the above factors should never be a decisive factor in the field officer's guess as to the manner of death. Statistics have very limited application to individual cases. However, if a large number of things about the incident being investigated are consistent with the above, he/she might want to take another look before deciding that it was not homicide.
Motive is not strictly an element of the crime in homicide. However, you will find it difficult to convince a jury that someone killed a person, unless you can tell them why he/she did it. The three common motives for murder are sex, property, and insults. Sexual rights are a more common female motive. Property disputes are a more common motive when the killer was poor. However the most common motive for murder in general, is the petty argument or insult.
SUICIDE IN GENERAL
Insurance policies typically do not pay off in cases of suicide. Many suicides can look like accidents or homicides, and some accidents can look like suicides. Sometimes the suicide victim will plan it that why. A determination of suicide is of very practical interest to a number of different parties beyond the immediate family.
Even an obvious suicide should be thoroughly investigated.
Combination of methods....
It is typical of a suicide that the victim will try a combination of methods. Slashed wrists, gunshot wounds, hanging, overdose; whatever the method of apparent suicide, look for evidence that the victim tried a second or even third method will waiting for the first to take effect, or after the first method apparently failed. This will buttress the eventual finding of suicide as the manner of death.
Hesitation wounds are also typical, or some evidence of a testing of the weapon. For instance there might be a round fired into a wall "just to make sure the gun works". A self-inflicted knife wound typically has several smaller, superficial cuts quite close to it.
Multiple severe wounds are possible in a suicide. In one recent suicide in Duluth, the victim had two bullet wounds in his/her head, closely spaced, from the same gun, even though the first wound was instantly fatal. It is believed that a muscle spasm caused the second firing. In another recent Duluth case, an older model revolver was found cocked in the hands of a lady who had died instantly from a self-inflicted gunshot to the chest. "Cadaveric spasm", the intense muscular contraction of the hands at the moment of death, is a well-established medical phenomenon.
While common wisdom might suggest that suicide victims would avoid severely painful methods of suicide, this is not always true. Psychotic suicide victims sometimes mutilate themselves in bizarre and very painful ways.
When weapons are used in a suicide, you expect to find them at the scene. When they are not, you must establish an explanation. Occasionally, the victim will arrange for some remote-control removal of the weapon. Friends or relatives of the victim will disturb the scene of the suicide, and even remove and hide the weapon. Their motive for such acts may be financial or emotional. Regardless of the reason, your challenge will be to recover the weapon and account for its movements.
Suicide notes are very helpful in establishing the manner of death. Always look for them; they may be hidden in places significant only to the victim. The suicide note should always be fingerprinted, and samples of the victims handwriting should always be gathered for comparison with the note. In most cases, the note will be written in a very tense, scrawling hand. However, in cases of deeply depressed persons suffering from long-term anxiety, the decision to kill themselves may actually sooth them. Their handwriting may reflect this.
Depressed suicidal people will frequently set a specific day sometime in the future for their suicide. This seems to make them feel better, and their loved ones will notice that they had seemed more cheerful and relaxed. They may continue to make plans as if they intended to continue living, but may tell friends that something special will be happening on the appointed day.
Many suicides are accompanied with some minor rituals. The gun may be cleaned before it is turned against oneself. Personal possessions may be arranged in an orderly display.
It is common in cases of self-inflicted wounds for clothing to have been pushed aside by the victim. Evidence of this is fairly indicative of suicide
Evidence of prior attempts at suicide, or threats of suicide, are helpful in determining that the manner of death was suicide. These possibilities should not be overlooked by the preliminary investigator.
2000 Minnesota youths between 15 and 24 will attempt suicide this year. 100 will succeed. This growing problem is probably caused by loneliness and inability to communicate, coupled with the normal stresses of growing up. Law enforcement officers will sometimes come across cases in which a young person, apparently happy and healthy, will kill himself or herself.
Only 30% of these young suicides have left notes that ever got found. Don't neglect to look in their school lockers.
Typically, more young females attempt suicide. However, more males succeed, probably because they tend to use more violent methods.
ACCIDENTAL DEATH IN GENERAL
Many insurance policies pay double if the victim dies accidentally. Furthermore, negligence is frequently claimed against various allegedly responsible parties in an accident. Thus a finding of "accidental death" is not a matter to be taken lightly. A reasonably thorough investigation is called for in every death.
Witnesses to an accidental death should be evaluated as critically as any other witness. You should always be wondering if they have a motive for lying. Listen not only to the content of their statements, but also to the degree to which they seem to be trying to convince you to accept their interpretations of what they saw. Even an overstated disclaimer ("I don't know what it means, I just want to tell you what I saw!") might warn you, in some cases, that a witness is worried that you will realize that he/she has an interest in the results of your investigation.
NATURAL DEATHS IN GENERAL
A natural death is by far the most common death investigation. Although most of this training is directed at convincing you that some deaths that appear natural are in fact not, we do not intend to discourage you from accepting a natural death as it appears. We do however, want you to be alert to things that are inconsistent with the presumed cause of an apparent natural death.
To that end, a diligent field officer will take some time to evaluate the symptoms that witnesses describe in the victim prior to his/her "natural" death. A call to the medical examiner AND the victim's doctor is usually in order, to determine if such symptoms are typical of the victim's disease.
Do Not Resuscitate Orders....
In Minnesota, a terminally ill person may execute a Do Not Resuscitate Order, authorizing first responders and EMT's to allow them to die even if resuscitation is possible. Such orders must be signed by both the patient and his/her personal doctor or a judge. Of course, you would always be better off resuscitating if you had any question about the validity of the Order. Consult the policy of your local jurisdiction for guidance.
Medically, the definition of death is up in the air, due to recent advances in medicine. For our purposes as death investigators, a person is death if he/she looks dead. That is, he/she isn't breathing, his/her heart isn't working, and he/she isn't responsive. He/she is also "dead" for our purposes, if he/she is obviously and irreversibly going to die. However, a person is not technically dead until his/her brain has totally and irreversibly stopped working.
Medicine also does not have a good, accepted definition of asphyxia. It is basically a loss of the brain's oxygen supply, either through a breakdown in the blood pumping system, or in the respiratory system's ability to put oxygen in the blood. In the strictest sense, every death, even a severing of the head, is an asphyxia death.
Cyanosis is characteristic of certain manners of death. It is a bluing of the outer skin, caused by lack of oxygenation of the blood in the skin. Note that a simple loss of the blood in the skin does not cause this effect; the blood has to be there and be oxygen poor or the skin will not turn blue.
petechiae ("pet ee' key a")....
Petechiae is a display of small, non-elevated (not bumpy), red spots on the skin. It is caused by the bursting of small blood vessels in the outer skin, under pressure, and is characteristic of a higher than normal blood pressure in the skin. It is characteristic of certain causes of death. Any condition that causes usual pressure in the skin may result in petechiae. Even the dangling of a dead limb off a bed may cause petechiae in the limb, after death. Petechiae can be caused by difficult births, by extreme constipation, and other less common medical conditions.
Petechiae may also result from the breakdown of the tissues at the beginning of the process of putrefaction, especially in the areas of lividity.
ESTIMATING THE TIME OF DEATH
It is frequently helpful to be able to make some on-the-scene judgments as to approximate time of death. Unfortunately, there is no accurate way to establish time of death merely by observing the body. It is far more useful to establish it by other means, such as witnesses, neighbors, unopened mail, or other testimonial or physical evidence. However, the condition of the body is sometimes the only means available for the field officer to estimate the time of death.
The information listed below should be used only for approximations. If it indicates a time of death radically inconsistent with other evidence, then further investigation would certainly be in order.
The human body typically cools at an average of 1.5 degrees per hour. Typically, it take the body 18-36 hours to cool to the ambient temperature. These are merely averages, though, to be used as a rule of thumb. There are many variables that can affect the cooling rate, such as the temperature surrounding the body, air movement, original body temperature, body weight, body fat (fat guys cool more slowly), clothing, and the surface on which the body is lying.
Medical examiners can take a "core" temperature to get the most accurate measure of the body temperature. Field officers can feel between legs, in armpits, or in other protected areas of the body to approximate core temperatures and get a rough idea of time of death. If such protected skin is still somewhat warm to the touch, it has only been 1-2 hours. The protected skin does not become cold and clammy until after 18-24 hours. These time estimates apply only to protected, indoor environments.
The eyeballs typically dry out within 15 minutes of death. This assumes, of course, that they are open. 3-4 hours after death, they will take on a brownish color ("tache noire") in the whites of the eyes, in the areas not covered by the eyelids.
At the time of death, the blood stops bringing fresh oxygen to the muscles. The muscles continue to live long after the brain has died, using the oxygen left in the body. As the muscles begin to die from lack of fresh oxygen, they quit producing Adenonine Triphosphate (ATP), which is used by the muscles to process glucose and actin. Once the ATP remaining in the muscles is exhausted, the fibrous cells of the muscles, which normally slide past each other freely, become glued together by the glucose and actin. This produces the stiffening effect called rigor mortis.
The basic factor affecting the timing of rigor mortis is the amount of excess ATP in the muscles at the time of death. ATP is usually present in the muscles, but exercise depletes it. In the case of an exhausted person suddenly dying, there might by no ATP left whatsoever, and rigor mortis would begin very quickly. For the same reason, drowning victims typically go into rigor mortis very quickly. In the struggle to stay afloat, they exhaust their supply of ATP.
Some of the other factors affecting the onset and progress of rigor mortis are the initial temperature of the body, the ambient temperature, humidity, food in the stomach, and the presence of certain molds and bacteria both in the body and the environment. The age and fitness of the deceased also affects it. The times listed below are only typical averages for a typical indoor American environment.
Rigor mortis typically begins within 2-4 hours. It begins simultaneously in all the muscles, but is apparent in the smaller muscles first, such as the jaw muscles. It progresses through the body for a period of 6-8 hours. After 36 hours (or as long as 6 days), secondary flaccidity may take effect, caused by the deterioration of the muscle tissues. However, in some cases, secondary flaccidity may not take place at all.
Rigor mortis is probably more useful to the investigator in determining whether or not the scene or the body have been disturbed since the death. Rigor mortis itself usually does not change the position of the body. The body merely stiffens in the exact position in which is it lying. Even a person who has died a very painful or dramatic death, will relax as they lose consciousness prior to death. The body should be in a relaxed position consistent with the cause and mechanism of death, if it has not been disturbed.
Intense heat in the environment, however, can change the position of the body. It is common in the case of fire deaths, or of a body subjected to intense heat after death, for the muscles to contract due to radical drying of the tissues. This causes a characteristic "pugilistic attitude" (arms and legs drawn into a boxer's stance) regardless of the original position of the body.
Livor Mortis (lividity)....
When the heart stops at death, the blood quits flowing, and blood pressure drops to zero. Under the influence of gravity, the blood then slowly drains to the lower-lying parts of the body. On the surface of the skin, this shows as a paleness to the upper portions of the body, and a darkredness of the lowest-laying parts of the body.
Lividity typically begins within 2 hours of death; sometimes it begins to show within minutes. Within 8-12 hours it becomes relatively fixed. That is; it will not quickly drain back out if the body is moved. In some cases, however, it will never become fixed. In 3-5 days, lividity may become permanent.
In some older persons, lividity may never occur at all. This is caused by the poor condition of their circulatory systems prior to death, or low iron or oxygen content of the blood.
Lividity can look similar to bruising. However, bruising won't change color in a dead person, if you push on it with your finger.
Your medical examiner may be able to tell you some things about the time of death based on changes to the contents of the stomach. The normal digestive process stops a short time after death. The food in the stomach or intestines then changes state (rots) as it would in any warm, wet, highly-bacterial, enclosed environment. Since different types of food change states at different rates, some information can be inferred from the state of the food at the time of autopsy.
These determinations can only be made at the autopsy. However, the medical examiner will need certain information from the field officer in order to make them. He/she needs to know when and what the deceased last ate. The field officer must look for evidence and testimony to establish this, if time of death might be a factor in the investigation.
The stomach of a living person will empty itself through the normal digestive process, in 3 hours.
Like all of the other post-mortem change processes, putrefaction (the process of decaying) proceeds at a rate that varies with a number of factors. If the body is in a frozen environment (such as a Minnesota forest in winter), for instance, putrefaction may not take place at all. Putrefaction is a longer-term process than the other post-mortem changes, and so is even more dependent on the environment.
The following schedule of putrefaction changes is "typical" for a normal American indoor environment:
Within 2-3 days, a greenish discoloration will be visible in the area of the cecum and stomach (the belly). The body will begin to smell.
After 1 week, the trunk of the body should be greenish-purple. The skin is typically marbled a purple-brown along the network of the blood vessels. The skin loosens and slips easily off the body. The odor is quite strong.
After 2 weeks, the skin typically blisters as pockets of gas are trapped under it. The trunk becomes swollen and distended. Black fluid seeps from, or accumulates in, all of the body orifices.
At 3-4 weeks, the body is typically fully ballooned. The face is greenish-purple and bloated. The hair and nails are loosened. The odor is overpowering.
Even maggots, distasteful as they may be, can help determine time of death in some cases. This is usually only useful when the death has occurred within two weeks.
Flies may begin to lay eggs in the eyes, orifices and open wounds of the body with a few hours. Most species of fly only lay eggs in the daytime, but some only lay eggs in the nighttime. This might be useful if the death had occurred within 12 hours.
These eggs can hatch within 24 hours. The maggots will be fully grown within 4 days. They will become flies within 2 weeks, and may lay a second generation of maggots.
To use the maggots to establish the time of death, collect a sample of the oldest, largest maggots. The medical examiner can submit them to an etymologist, to establish their age.
Other bugs also help to establish time of death, in some cases quite firmly, especially at an outdoor scene. However, its a very technical business. If you believe that time of death is going to be a serious question in your case, contact a forensic entymologist for instructions on collecting specimens. If its a homicide case, don't try to do this yourself; the BCA is has specially trained technicians to do it.
When the body lays in a warm dry environment with enough ventilation, it may become mummified. This is an exception to the normal putrefaction process. In these cases, the body will be fully dried out, and the skin will be leather-like. This process takes about one year.
In some circumstances, external bacteria may combine with wet conditions to turn the body tissues into a soapy wax-like substance. This is a rare situation, called adipocere and usually only involves part of the body. It is more likely to occur under water.
In water, the processes mentioned above typically take place only half as fast as in air. In cold waters, such as are typical in Minnesota, it is even slower. Drowning victims, however, typically go into rigor mortis very quickly