This section will discuss some of the various things that can kill people. The unusual and/or specific profiles of these causes of death will be listed, to assist the field officer in evaluating the consistency of the available evidence and testimony


Acute illnesses are diseases and disorders that kill people without warning, such as a heart attack. The opposite is a chronic illness, which the victim typically knows about for some time prior to it killing him.

Heart Attacks; CVA's...

Law enforcements officers go to lots of acute heart attacks. The victim should be cyanotic in most cases. He/she should have experienced chest pains, or pain in the arms or neck, prior to falling down and losing consciousness. A prior history of heart problems in the victim is not necessary.


An annuerism is a sudden bursting of a blood vessel. A major annuerism in the heart, stomach, or head is typically fatal.

A cranial annuerism, (a stroke) unless it is very small, interrupts the blood flow to the brain, and also results in a pool of blood inside the skull, which squeezes blood out of the other parts of the brain. The eyes tend to roll towards the point of bursting after death. The victim will have lost consciousness almost instantly, if it was a large annuerism. Smaller cranial annuerisms can also kill, but the victim will have exhibited symptoms of confusion and loss of motor coordination.

An annuerism of the heart itself, will cause sudden loss of consciousness. An annuerism of one of the coronary arteries will cause sudden extreme pain, without any prior symptoms. The annuerism of even a small artery of the heart may be fatal, but death may be fairly slow. However, it is still extremely painful, so much so that victims have tried to kill themselves prior to expiring naturally.

Stomach annuerisms.....

A major stomach annuerism kills because of the large blood loss. The victim will lose consciousness quickly but not immediately, because of the rapid drop in blood pressure. A stomach annuerism large enough to cause death will fill the stomach rapidly with blood. The victim will expel this blood violently, so that the scene will be dramatically splashed with blood. It may be so bloody that your first impression will be homicide.

Pulmonary Emboli....

A pulmonary embolism is a clot in the lung which interferes with the ability to breath, leading to asphyxia. A person who dies by pulmonary embolism will be cyanotic, and show some other symptoms of choking.


The death of a chronically ill person is no surprise. The family will usually tell you of the illness. Typically, of course, such people die in the hospital, but more people recently have been choosing the "dignity" of dying in their own home. Law enforcement officials should be aware, in such cases, of the temptation for the family to indulge in euthanasia ("mercy killing") and take careful note of the testimony of the relatives who claim to have witnessed the final minutes. This is especially true when the illness was painful or uncomfortable, or otherwise difficult for the loved ones.

Out of respect for the bereavement of the family, of course, the officer should be sensitive and diplomatic. But don't let this stop you from asking the relevant questions and keeping an objective frame of mind.

The attending physician should always be contacted to confirm the existence of the chronic illness. You should get the correct spelling and pronunciation from him, so that it can be relayed to the medical examiner or coroner. You should also verify the symptoms that have been described to you, to assure that they are consistent with the supposed illness. Likewise, you should relay the symptoms to the medical examiner, for a second opinion.


A SIDS death is defined as one in which an autopsy reveals no other explanation for the death of an apparently normal, healthy infant under the age of one. This is the official medical definition. It reflects the fact that there is no medical explanation for the fact that 1/5 of one percent of all babies die for no apparent reason. Research into SIDS has learned only that it appears to be related to respiratory problems.

One out of every 500 live births will become a SIDS death. SIDS has been around at least since the Egyptians, and is a worldwide phenomenon. It is not caused by smothering, becoming tangled in blankets, a virus, or a bacteria, neglect or abuse.

Families tend to blame themselves for the death of a SIDS victim. So do their friends and relatives, sometimes tearing families apart. In a Nebraska study, it was found that 60% of the families of SIDS victims left the town where it happened within two years, presumably because of the difficulty of dealing with the stigma of "allowing the baby to die." In truth, they could not have prevented the death of the baby.

The only way to determine that a baby died of SIDS, is to do an autopsy. If the autopsy and the investigation eliminate all other causes, then it can be called a SIDS death. Remember the definition of SIDS; that there is no other explanation.

The victim of SIDS will be a normal, healthy, well developed infant under one year of age. He/she may have had a slight respiratory infection or rash, the day before the death. The death occurred while sleeping, typically but not always overnight. The body will be cyanotic. The body may have had some spasms after death, possibly becoming entangled in the bedclothes. There may be a foam or bloody foam at the lips or nostrils.

Most SIDS victims are 2-4 months old. More SIDS cases occur during the winter months. There is no definite victim profile of a SIDS victim, other than that he/she will have been a normal healthy baby. Among the characteristics that appear slightly more often among SIDS victims, however, are the following:

Since the above characteristics coincide strongly with the profile of child abuse homicide victims, it would seem that some homicides are being passed off as SIDS. Field officers should therefore be diplomatically skeptical, when dealing with what otherwise looks like a SIDS death, especially if the above profile fits.

The most common way to kill an infant, which would look very similar to a SIDS death, is to smother it with a pillow. Even with a baby, however, this takes a good deal of pressure. Such pressure will leave observable marks on the body. Look for bruises on the face and along the gum lines on the inner side of the lips. Neither petechiae nor bruising of the face is a symptom of SIDS, but they are typical of pillow smotherings.

While it is not possible for a baby to smother in its blankets or pillows, accidental deaths do occasionally happen in cribs. Older cribs sometimes do not have adequate safety features. It may be possible for a baby to slip down between the mattress and frame. If such an accident causes a mechanical distortion of the airway, the infant may die of positional asphyxia.


The killing of a child for which one has a parental or other caregiving responsibility, is called child abuse homicide. Child abuse occurs in all social, ethnic, and economic groups. It is, however, a definite behavior pattern, and as such has a "typical" profile.

Child abuse homicide will kill 1 out of every 1000 kids. It accounts for 4000 deaths per year in America. It is the second most common cause of death in toddlers.

victim profile....

1/3 of the victims are under 6 months of age; 1/3 are between 6 months and three years old. The victims tend to belong to low-income, female-headed families, or are step-children. They tend to have been premature or born out of wedlock , and are typically the youngest child in the family. After allowing for differences in socioeconomic status, there is no difference in the occurrence of child abuse among the different ethnic groups.

abuser profile....

Only 10% of abusive killers are psychotic; the rest are supposedly normal emotionally and mentally. They were typically abused as children themselves. The fatal abuse is typically "provoked" by some "misbehavior" on the part of the child.

the abuse profile....

"Battered Baby Syndrome" has received a good deal of publicity. It refers to patterns of injuries observed on children who are the victims of physical child abuse. Such children have multiple healed fractures, old and new burns, bruises, facial injuries and injuries to the genitalia. They tend to be very quiet and shy children, and may be thin and nervous. However, battered babies make up only a portion of the victims of child abuse homicide.

Only 50% of child abuse homicides are the result of repetitive assaults. Another 25% are single-incident assaults. These tend to be the middle class families, and the injuries tend to be shaking injuries. You may not see a pattern of old injuries on this victim.

The remaining 25% are the result of neglect. These babies died of starvation, hypothermia, or lack of the most basic medical care. The parent of such a victim typically will belatedly pamper the body, washing it, putting nice clothes on it, and combing its hair prior to notifying the authorities or taking the body to the hospital. This does not usually fool anyone.

warning signs.....

When responding to the report of the death of a child, officers should be alerted to the possibility of a child abuse homicide, if there is a pattern of old and new injuries on the victim. Likewise, unexplained injuries, or bizarre explanations should warn the officer that a more thorough investigation may be called for.

Any unusual delays in reporting the death should also alert the officer. Most child abuse homicides (80%!), are not reported until at least 8 hours after the death.


Minnesota also has laws making it a crime to unreasonably neglect or endanger a child. The death of a child should be evaluated to determine if such endangerment or neglect was a contributing factor. PLease refer to Minnesota Statute 609.378. Since this is a relatively new statute, its application to particular circumstances has not been defined by the courts yet. Consult with your County Attorney for guidance. The crime is a gross misdemeanor, so you should not make an on-scene arrest in any case (assuming that it did not occur in your presence)


Choking is distinct from strangulation. Choking is a blockage of the throat or lungs. Choking is usually associated with accidental death. Typical cases are a person eating and drinking alcohol, and getting some food lodged in their windpipe. Children occasionally get small objects caught deep in their throats. It is rare for them to die of such things, unless some well-intentioned rescuer has pushed the object further into the throat in an attempt to dislodge it. First aid procedures are now taught to the general public, which has reduced the number of people who die from such accidental chokings.

Occasionally, when an unwitnessed death is investigated and there is no immediately apparent manner of death determined, an inexperienced medical examiner may make a erroneous discovery that the person died as a result of choking. This happens when the medical examiner, at the autopsy, finds stomach contents in the airway. He/she may have neglected to consider that the body has been moved about by the transportation people since the death, and that the stomach contents are free to slosh around during that handling. Sometimes the stomach contents move into the upper trachea, and then into the previously clear airway.


There are two distinct types of strangulation; manual and ligature. Each leaves different evidence on the body. In strangulation deaths, over half of the victims become incontinent before dying. This is a far less frequent occurrence in other causes of death.


In these cases, death can be effected by either the closing of the airway or the restriction of the blood vessels too and from the head. A manual strangulation (meaning, the victim was throttled by someone's hands) cannot be a suicide; upon losing consciousness, the victim would release his/her grip and revive.

The victim may be cyanotic in the face and scalp. Other areas of his/her body will be non-cyanotic. He/she may have petechiae in the head. The body would typically show abrasive markings on the neck where the strangler's fingers gripped it, and you might find self- inflicted injuries on the neck where the victim tried to pry the fingers away.

You would typically find signs of a struggle in the area. Manual strangulation is typically used against relatively helpless victims such as smaller women, children, or feeble elderly people. The evidence of struggle should be evaluated in light of the relative strength of the victim and suspect. A small child, for instance, would not put up much of a fight.


A "ligature" is a rope, belt, towel, pair of pants; anything that can be tied or held around the neck to effect a strangulation or hanging.

Ligatures do a better job of closing off the veins in the neck. The victim will typically have a congested face, but the tongue will not be protruding. Petechiae of the face is typical of such cases.

The ligature leaves a discolored dent in the skin of the neck, completely encircling the neck. The ligature mark may be incomplete, if the ligature was twisted to make it tighter. This is different from a hanging mark, which leaves a V-shaped mark with incomplete encirclement. Tight collars, however, will leave marks similar to ligature marks, in cases where the body swells up during post-mortem putrefaction. Fatty folds in the skin of the neck can also leave similar marks.


Typically, the hanging victim will die because his/her airway was blocked. The force of the ligature is directed upward, rather than around the neck. This forces the jaw and tongue to block the airway. For this reason, the hanging victim will typically have a pale face and a protruding tongue. The inverted V-shaped ligature mark on the neck is characteristic of hanging deaths. This mark does not go completely around the neck, because the knot is usually pulled away from the neck as the ligature stretches and is pressed into the skin. The ligature mark may be indistinct if a padded or cloth ligature was used, but it will still be in the same shape.

Most, but by no mean all hangings, are suicidal deaths. Do not be in a hurry to write a self-inflicted hanging off as suicide. If there is a possibility of accidental hanging (see the section on sex-related asphyxia), do not be overly influenced by the presence of fingernail markings on the neck where the victim tried to pry the ligature away from his/her neck. Some instinctive prying at the ligature is common in suicidal hangings; this is a basic, purely physical, reflex which may occur even after loss of consciousness.

Sometimes the ligature itself can become an important piece of evidence in the investigation. For this reason, you should never cut, untie, or loosen the knots in the ligature. Save the knot for future reference. Cut the ligature along the bight where it is tied over the beam, door, pipe, or whatever. Leave it on the body for removal by the medical examiner. The medical examiner should leave the knot intact when he/she cuts it off the neck.

SEXUAL ASPHYXIA...and other sex-related accidents

Sex-related asphyxia is a bizarre form of accidental death. Persons who are susceptible to these accidents purposely strangle themselves with ligatures while masturbating, or have their sex partners strangle them manually. The reduced oxygenation of the brain reportedly gives them a heightened sexual experience. Some persons get the same effect by putting plastic bags over their heads or sniffing solvents. If they are careless, they can lose consciousness before rescuing themselves, and asphyxiate while unconscious.

Typically, the victim will have been masturbating just prior to his/her or her death. You will find erotic literature and pictures within the victim's view, and possibly a mirror. Cross dressing is also common in such cases. When hanging or some other strangulation method was involved in the accident, you will frequently find some padding between the neck and ligature.

Sometimes the sexual aspect of these behaviors is accompanied by the acting out of suicide, bondage, or torture fantasies. They may handcuff themselves, hang themselves, cut themselves, and even leave suicide notes. What makes it accidental, is that they did not really intend to kill themselves. You will find some self-release mechanism or self-rescue arrangement. Of course, if the victim died, the mechanism did not work. The investigator must determine why, if the "accidental" determination is to stick.

One might well suggest that such irresponsibly dangerous behavior is to suicide, what manslaughter is to homicide. Unfortunately, the law does not account for that, so it is a merely philosophical point. Sex-related asphyxia deaths are accidents, unless another person besides the victim is actively involved. When another person is involved in dangerous behavior which results in the death of another person, it is usually handled as a manslaughter case.

Bondage fantasies, when acted out in isolation, can leave the victim helpless if the self-release mechanism does not work. This may occasionally result in an exposure or starvation death, which would look at first like a homicide.


Deaths from hypothermia, freezing, and other exposure problems are not uncommon in Minnesota, for obvious reasons. Drunkenness is frequently a factor in exposure deaths; however this may not show up at autopsy because the alcohol would typically have been processed by the body in the time it takes to actually die from hypothermia.

People who actually freeze solid, can be revived; they are not dead. Hypothermia victims do not really freeze to death. Human beings can die from a lowering of body temperature to merely 60 degrees. Internal temperatures that low can interfere with the functioning of the body's internal organs, causing toxemia (internally-generated poisoning)and eventually death.

If the hypothermia process is observed, witnesses will describe a succession of shivering, stiffness, and confusion, followed by coma and death. The body will be pale and waxy, not cyanotic, because the blood will have been withdrawn from the skin by the body's defensive mechanisms, to avoid loss of heat.


A freezing victim will have the same appearance as a hypothermia victim, except that the skin will be frozen. Any alcohol that may have contributed to the accident will have been metabolized prior to death.

Some freezing victims have been revived even though the skin was frozen solid. If the internal core temperature of the body is at least 65 degrees, revival is theoreticly possible. Remember that it takes up to 36 hours for the human body to cool to the ambient temperature of a normal, dry environment, so the core temperature may be fairly high even after hours in extreme weather. Check carefully for a faint heart beat at the neck. Avoid rough handling, as this can send the body into shock.


The human body typically sinks shortly after death. It will resurface 3 days to 3 weeks after death. The surfacing is caused by bloating, which increases the volume of the body without increasing the weight. Sometimes, because of air trapped in the clothing on the victim, the body will not sink at all. In really cold water, the putrefaction process is very slow, and the body may not bloat up, so it will not resurface for a very long time.

Lake Superior is said to be too cold for a drowning victim to decompose, so that they never surface. The important questions in a drowning case are confirmation that the drowning was accidental and that the victim did in fact die of drowning. If the victim was dead prior to going into the water, then the characteristic indications of drowning will not be present. The testimony of witnesses should, as always, be taken critically and with an objective mind.

The existence of wounds on the body is not necessarily inconsistent with an accidental drowning. Bodies do get banged around in the water quite a bit, especially if they wash ashore. The injuries can be examined to determine of they occurred before or after death.

The body of the drowning victim will be pale rather than cyanotic. Since the body floats under the water after death with the head and limbs hanging down, you should see lividity in the face and extremities. The medical examiner should find lake water in the stomach. He/she should also see a fine sticky foam in the airway, which will ooze out the mouth and nostrils after several hours. This foam, which is the consistency of beaten egg whites and may be tinged with blood, is composed of proteins in the lung mixed with environmental water by convulsive breathing attempts just prior to death.

Do not overlook the possibility of revival of a drowning victim, if they have not been under the water too long and the water was sufficiently cold.


Even though the "liability" for an industrial accident is a civil matter, the police must determine how it happened. While the decision about whose "fault" it was is up to a civil jury, we must accumulate the facts while they are still fresh.

Every witness to the accident should be interviewed, at least informally. There is no excuse for failing to get the name of every eyewitness, whether or not they are willing to talk. In addition to finding out what the witness observed, you should record each witness's opinions. If they choose to change their opinions later, then they can explain what influenced them to do so.

Blood alcohol testing should certainly be done on the victim. Other persons who may have had a causal role in the accident should also be tested if they are willing. In some cases, there may be a company policy which will assist you in persuading appropriate persons to take a blood alcohol.

Occasionally, a company may attempt to refuse to let you on the property to investigate an fatal industrial accident. However, you (or the coroner if your county has one) have both the right and the responsibility to go onto private property and "take custody of the scene" in the case of a violent, unusual, or mysterious death. In extreme cases, you might have to arrest any person who interferes with you. You do not need a search warrant to go onto the property and take custody of and protect the scene, though you may well need one to search it.


50 volts can kill you, given enough current. High voltage can throw the victim a considerable distance from the point of contact with the electricity. In possible electrocution cases, if you do not have full confidence that the things you observe are consistent with electrocution, check with an qualified electrician.

Severe electrical shock can cause temporary paralysis by overloading the body's nervous system. If such paralysis prevents the victim from breathing, and he/she does not get assistance, he/she will die. Such a victim will have the general appearance of asphyxia. Many other electrocution deaths are caused by falls or other such accidents related to the paralysis.

The point of contact on the victim's body may appear as a small round, elevated, wrinkled burn spot. It will be grey-white or yellow at the center, surrounded by a blackened, burned ring. You should check for burns on the hands, feet and shoes, in addition to the entry wound.

Sometimes there will be an exit wound where the electricity jumped from the body. If so, it will have the general appearance of a bullet's exit wound.

Electrocution is not always the result of direct contact with electricity. Even residential neighborhood power lines can have enough voltage to jump several feet to a good conductor.


The general rule in Minnesota, as established by case law, is that every person participating in a sports event is aware of the risks involved and acquiesces to the actions of the other participants. Therefore, actions that might be criminal in nature under other situations, may be non-criminal in a sporting event. This assumes that the risks are reasonable, and that no specific intent existed to cause a death.

Nonetheless, the death of a person as a result of a sports injury is going to be a major incident, especially if the media was already there. Lawenforcement officers at the scene should treat every major injury accordingly. Spectators who might have had a particularly good view of the incident should be sought out. If game films are available, or if someone is video taping the game, a copy should be obtained.


In most crushing accidents that result in death, the chest was compressed, so that the victim could not breath. The victim dies of asphyxia.

In such cases, it is typical to find the blood redistributed to the extremities. It was squeezed out of the trunk by the crushing force. This is highly indicative of a crush asphyxia case. You should see petechiae over all of the non-crushed portions of the body.


Occasionally, fatal accidents happen in hospitals, clinics, and doctors offices. Some of these can be pretty spectacular; especially in the case of highly intrusive treatments that go wrong. These institutions are obligated to notify law enforcement officials of such accidents if they result in a death. We conduct an investigation, just as if it had happened at a local factory.

Hospitals employ legions of lawyers, and any lawyer worth his/her inflated fee is going to tell the hospital employees to not speak with the police about the accident. They are ,of course, worried about their clients\'s financial liability and reputation, and quite rightly so. Nonetheless, it is our responsibility to gather the facts and establish what happened.

The initial responder will have the best chance of getting candid statements. They get there before the lawyers and may find the nursing personnel most anxious to describe the incident. Therefore the field officer should listen very carefully to what the staff says, and take notes as fast as he/she can. If the note- taking seems to worry any witness, the officer should stop taking notes, and just listen.

Hospitals are highly regulated. Various state and federal agencies have extraordinary powers to commandeer hospital records and demand testimony from hospital employees. However, these agencies do not feel the same urgency as law enforcement in dealing with a problem, so you may find them aggravatingly slow.



Most household poisons are acidic. The medical examiner will find reddened intestines and holes in the stomach, and possibly other burn-type injuries. It is helpful in these cases, to gather samples of the possible poisons.

The victim may show some reddening or browning of the mouth or lips. They may have vomited prior to death, or expelled blood from their mouth.


Arsenic, lead, mercury, cadmium, and antimony are all naturally occurring heavy metals. They are chemical elements, rather than combinations of other elements. They interfere with the function of some of the basic chemical processes that sustain life.

Since they are usually present in the natural environment in only very small concentrations, the most likely source is a misused manufactured substance, or environmental pollution.

Heavy metals may be used by clever murders who have access to their intended victims, in small doses over a long period of time. Used in this fashion, they produce the appearance of a chronic illness, eventually leading to the death of the victim.

Arsenic is typically found in non-systemic rat poisons and similar preparations. 1.5 grains of arsenic is fatal to humans.

Mercury and lead interfere with the nervous system. including the brain. Victims of such poisons exhibit bizarre, irrational, even violent thinking. In fact, the fall of the Roman Empire has been attributed, by some historians, to the fact that the ruling class began lining their wine jars with lead. Lead is found in some older house paints, which can be fatal to infants if they chew on chips of it.

Antimony is not commonly found in substances around the house. It is in some brands of gunpowder. If ingested, it causes sudden death, even in fairly small doses. The medical examiner will find reddened intestines and holes in the stomach, similar to acids burns. Antimony preserves the body; it may not putrefy for years.


Most vegetable poison act as a depressant on the central nervous system. Examples are barbiturates, opiates, belladonna medicines, strychnine, sleeping pills, and chloral hydrate. Death from an overdose of any of these vegetable poisons, is caused by the depression of the central nervous system, causing paralysis of the lung and heart muscles, leading to asphyxia. If the death is witnessed, the witnesses should have seen a progression of drowsiness, delirium, and coma. There may also have been convulsions.


Poisonous gases represent a special hazard for the first responders. In any case where the cause of death is not immediately obvious, and the victim is in a low-lying or non-ventilated location, officers should worry about their own safety. Many poisonous gases are heavier than air, and accumulate in such areas. Some are odorless.

It may be too late to be safe, after you figure out what killed the original victim.

Hydrogen sulfide....

Hydrogen sulfide is also known as sewer gas, because it is produced by the natural decay of vegetable matter. It is heavier than air, and is usually present in small concentrations in sewers, septic systems, and swamps. It is one of the most dangerous poisonous gases, because it is so common. In heavy concentrations, it can cause instant unconsciousness. The victim then falls to the ground, where the concentration is still heavier, and breaths a fatal dose.

Field officers should be particularly cautious of approaching a victim of hydrogen sulfide poisoning. It would not be unreasonable to treat any situation in which a person is unconscious in a low-lying, poorly-ventilated area, as a hydrogen sulfide poisoning until and unless it is proven otherwise.

Hydrogen sulfide has the characteristic rotten-egg smell of sulfur. If you get even a whiff of rotten-egg smell while approaching a "man down" in a low-lying area on a windless day….turn around and move to higher ground immediately.


Phosgene is chemically related to chloroform and carbon-tetrachloride. It used to be a by-product of some special purpose fire extinguishers. If those fire extinguishers were used improperly, and sprayed on a very hot surface, phosgene formed, sometimes killing the user. The user would then be found, typically, as the apparent victim of what had started as a relatively harmless fire.

Most of these fire extinguishers have been recalled. Some, of course, remain out there, and occasionally result in some hard to explain "fire deaths".

Carbon monoxide....

It takes a concentration of 4 parts per thousand of carbon monoxide for an hour to kill a human being. The victim's skin typically turns cherry red or cherry pink. Although it is said to be a relatively painless way to die, it is not so pretty after loss of consciousness. The victim goes into convulsions, violent enough to move the body several yards and/or contort it into positions that may seem hard to explain.

It is not unusual for suicidal carbon monoxide victims to lock or even nail the garage door shut, and put padding around supposed air leaks. The authors have personally observed that several such victims have also unscrewed the light bulbs in the garage, for reasons that we cannot explain. The investigation into an automotive carbon monoxide poisoning should always address the fact of whether or not the car was running at the time the death was discovered. If the first responder finds the car not running, he/she should account for this prior to concluding his/her investigation.


Jumping suicides seem to be more prone to leaving notes than other suicides. They may not, however, leave them in obvious places. Check the car, purse, apartment, workplace, and school lockers, as appropriate.

Check the body carefully for defense wounds. This will be complicated by the other trauma injuries, from the fall itself, but must be attempted if foul play cannot be ruled out by witnesses. Also check the body and clothing for marks and trace evidence that might have been picked up along the path of the fall. This might tell you something about the trajectory, and hence the horizontal speed at which the victim left the point of falling.

Check both the impact and departure points carefully for evidence.

A subdural hematoma is a blunt force head injury resulting in bleeding inside the skull. If you have an unexplained fatal subdural hematoma, you should always consider the possibility of death by falling. 72% of all fatal subdural hematomas are caused by falls. (25% are traffic injuries, only 3% are caused by other means, such as blows.) One key that a subdural hematoma is present, is that the victims eyes will roll towards the injury, due to the mechanical pressure of the build-up of blood under the skull.


Bruises may be distinguished from lividity by pressing on the discolored skin. Bruises will remain discolored, while lividity will temporarily turn white. This will not work after lividity has become permanent.

Bruises may be more difficult to see if they were made immediately before the death. They take a while to develop even in a living person, and may not develop at all in a dead person. Bruises of course, are merely the external sign of an internal injury. They are caused by the bursting of small blood vessels near the surface of the skin. The more significant injury, if there is one, is inside the body. Many internal injuries do not show at all on the skin, especially if they happened shortly before death. They may not be discovered at all until the autopsy. In cases of unexplained death where blunt force trauma (beatings, falls, kickings, etc) are a likely finding of the autopsy, first responders will have to gather there on-scene evidence before the cause of death has been confirmed.

Cerebral concussions....

A cerebral concussion is similar ( in layman's terms) to a sub-dural hematoma. It is basically the bursting of capillaries (very small blood vessels) in the brain. Blood accumulates in the brain, and can eventually lead to death, typically after a succession of dizziness, nausea, confusion, and coma. A concussion is usually caused by a blow to the skull. There may be no external signs of the injury whatsoever, but there could be a goose-egg over the injury sight.

Alcoholics are more susceptible to concussions, for reasons that are not clear.


Obviously, the vast majority of traffic fatalities are accidental deaths. Every police officer has been trained in the investigation of such incidents. However, the simple fact that it is a traffic case is not sufficient to make the death accidental. In addition to the other work you do at traffic fatalities, take a minute to evaluate the possibility that the incident was intentional in nature.

Traffic fatalities can be suicidal or homicidal in nature. They have also been used to cover up homicides, with the dead body being placed in the vehicle prior to the crash.

Criminal Vehicular Homicide....

Minnesota law makes it a serious crime to drive a car in a grossly negligent manner if the driver causes an accident resulting in a death. Furthermore, the police have special powers to require the driver to submit a blood sample if they have probable cause to believe he/she committed Criminal Vehicular Homicide while drunk. You may take such a sample by force if necessary. This is an exception to both the Implied Consent Law and to the general search warrant requirement. The justification for the exception appears to be that blood alcohol level is a perishable piece of evidence relevant to a serious case.


A person who has been smothered by placing a hand, pillow, or similar object over the mouth and nose, will typically have characteristic injuries. There should be scraping injuries to the face in the area of the mouth and nose, if a bare hand was used. This might also produce fingernail puncture marks. Even if padding was used, it takes considerable pressure to cut off all the air, and you should see bruising as a result.

Most characteristic of pressure-type smotherings, are the markings on the inner lips were the lips have been pressed into the teeth or gums. These impressions should be easily visible to the untrained eye.

It is not possible for a person, even a baby, to smother as a result of having a blanket or pillow accidentally over their mouth. There has to be considerable pressure over the mouth to form a sufficient seal through such material.

It does not take nearly as much force if an impermeable material such as plastic or even very closely woven fabric is placed over the mouth. Even the natural vacuum of breathing can form enough of a seal in such cases. Paint sniffers occasionally die when they pass out prior to removing the baggie from their mouth, and subsequently smother. If a plastic bag is merely placed over the head, it is sufficient to kill the victim; it need not be tied at the bottom.

Contrary to popular belief, the medical examiner cannot test for trace chemicals to establish that the victim was smothered with a plastic bag. If you do not find physical traces of it, you will have to rely on other means to establish the instrument of death.

Evidence of hand restraints on the victim of such a death should be looked for in every case, to help eliminate or substantiate homicidal manner of death.

It takes about 90 seconds for a person to lose consciousness without air. The brain begins to die in about 4 minutes.


Every fire is assumed to be an accident, as a matter of civil law. We have to prove otherwise by preponderance of the evidence if we believe it is a suicide, or by proof beyond a reasonable doubt if someone is charged with arson.

Unusual changes in the body.....

In hot fires, the skin and fat may split, and may leave a false wound somewhat similar to a knife wound. Muscle typically does not split.

The heat of the fire may also draw the body, or a portion of it, into what is called the "pugilistic position" (Boxer's stance). This is caused by the radical drying of the muscle tissues, shrinking them. This may raise an arm or leg into the air from where it should be (see "post mortem changes....rigor mortis), or otherwise move the body into an unnatural position. This phenomenon may help you figure out where the hottest part of the fire was relative to the body.

Point of Origin.....

Figuring out where the fire started is the first basic step in a fire investigation. The fire can be traced backwards; parts of the structure that burned hotter and longer will show more damage and deeper charring. Patterns of charring typically point in a V-shape towards the point of origin. The point of origin is where some of the best evidence is, in an arson case.

Ignition devices, matches, timers, and other things related to the start of the fire may be at the point of origin. (Of course, the firefighters could easily have moved them in the fire-fighting effort, too. We just have to live with that problem.) There are so many possible time delay methods, that it is best to assume that anything out of place near the point of origin could be part of an ignition timer.

Accellerants (gasoline, alcohol, whatever) that were used to get the fire going will typically not burn completely off. You should be able to smell it at the point of origin, and even get an unburned sample. This sample should be sealed in an air-tight clean container, and submitted for identification to the BCA or any helpful insurance laboratory. If the accellerant has burned completely off, you may still be able to identify it if you collect any unusual-colorred ashes at the point of origin.

The fire scene....

Although firefighters usually make a real mess of the scene of even a small fire, we have to try to reconstruct the scene as it was before the fire. This is a nearly impossible challenge, but should be attempted. If the firefighters can be persuaded to try to remember what they did inside the various rooms of a structure you may be able to tell if anything else was moved after the fire started. Also ask the firefighters if they lost anything in the fire, in case something foreign to the scene is later found there.

If you have an arson suspect at the scene of a fire death, do not let him/her anywhere near the scene. Fires leave plenty of trace evidence on those who start them, but if the suspect gets into the scene, the evidence on him/her will be meaningless.

One essential question at a fire death is whether or not the victim was alive at the time the fire started. The victim, if he/she died as a result of the fire, typically died from the poisonous gases released by the fire, not the heat. Nonetheless, there would usually have been considerable smoke present prior to the death. You may see concentrations of smoke around the lips and nostrils if the victim was breathing when the fire started.

The victim may also have breathed carbon monoxide prior to death if he/she was alive when the fire started. While the concentration of carbon monoxide may not have been sufficient to turn his/her skin red, it will still show up in his/her blood at autopsy.

Blistered skin may also help establish that the victim was alive when the fire started.


Bullets typically leave a small, clean entry hole in the body, and do massive internal damage as they travel through or bounce around in, the body. If the bullet exits the body, the exit wound will be evulsed (tissue projecting outwards above the skin's surface) and much larger than the size of the bullet. The path of the bullet through the body is not necessarily a straight line, nor is it in line with the flight of the bullet. Thus, the exit wound does not tell you much about the direction from which the bullet came.

The entry wound can be probed to get a rough idea of the direction from which the bullet came. However, this should be taken only as an approximation, keeping in mind that it could be way off, too.

Suicidal shootings....

An old cliche in police work holds that women never shoot themselves in the head or face. It is not true.

It is not uncommon for suicides to move clothing aside before shooting themselves, rather than shoot through the clothing.

Estimating the distance .....

There are several things that can be analyzed to estimate the distance from which the gun was fired.

The patterns of tattooing, soot, charring, and bullet fragments can be compared with test firings of the weapon and ammunition, to establish a range of distances between the gun and the victim. These are just estimates, but are fairly accurate, especially if the weapon was close to the victim. In order for any of the analysis to be done, however, the weapons and the particular ammunition that was used must be submitted to the lab. Do not attempt to do the test firing within your own department, unless you have a court-certified expert on hand.

If it is not known exactly what gun was used, or exactly what ammunition, then you must collect and submit all of the possibilities. This may mean searching several locations that the suspect could have had access to for weapons and ammunition. The lab may be able to determine which weapon/ammunition combination will produce the pattern of tattooing, soot, charring, and bullet fragments found on the victim.

Bullet fragments cannot be seen by the naked eye. They show up nicely, though on an x-ray. For this reason, the shooting victim should be x-rayed by the medical examiner before any clothing is removed, from several angles, to include closeups of each bullet wound.

Bullet wipe and abrasion rim are occasionally mistaken for some of the distance related trace evidence mentioned above. Bullet wipe is a dark grayish circle of oils left by the bullet on the clothing of the victim, around the entry hole. It comes from the oils used in the process of assembling the bullet at the factory. While it might be somewhat useful in confirming the brand of bullet, it tells you nothing about the distance from which it was fired. Similarly, abrasion rim tells you nothing about the distance. It is just the minor injury to the skin caused by the rubbing of the bullet as it pierces the skin.

The gun as evidence....

Do not be in a hurry to handle the gun at the scene. Even a loaded, cocked gun will not hurt anyone if it is left alone. Keep an eye on it, of course, and certainly do not left anyone near it until you are ready to collect it. (This is a good rule for any and all evidence at the scene.)

Once it has been decided how the gun will be handled, the collecting officer should secure it in a safe container. There are three objectives in deciding on a method of handling the gun:

  1. safety
  2. don't disturb any fingerprints or other trace evidence on the gun
  3. don't add any fingerprints or other trace evidence to the gun
Number (3) is over-emphathised in police work. It is okay (though certainly not desirable) to leave your fingerprints on a piece of evidence if (and only if) really necessary, as long as you are aware of exactly where you left them, and properly document it. Number (2), however, is underrated. Columbo the TV detective routinely picks up the murder weapon with his/her dirty handkerchief for a quick but discerning examination. Real cops leave it where it is until it can be properly photographed, measured, documented, collected, and packaged. Any method of moving a piece of evidence has potential to disturb trace evidence. Unless you are thoroughly trained, and have all the proper equipment in your back pocket, make a note that you saw the evidence, and leave it there.

The number of live rounds remaining in the gun, the number of expended rounds in a revolver, and the location of each round removed from the gun by the police must be recorded. In order to determine this information, it will be necessary to handle the gun quite a bit. Therefore, field officers should not try to get this information. Simply secure the scene and leave the gun where it is if that can be done safely. Otherwise, collect it carefully, containerize it and secure it, but don't open it up. Leave that for later.

Expended rounds should be searched for and collected. At the scene of an outdoors shooting, this may develop into quite a search, but it must be done. Fingerprints on the expended rounds can be very important evidence, so handle them very with tongs or other hard tools.


Knives and other stabbing or slashing weapons are gaining in popularity. They have always been a favorite weapon in sex-related and sex-gratification homicides. They also have historically been the weapon of choice for women. Multiple stab wounds are a characteristic of sex-related homicides.

When knives are used in a fight prior to the death of the victim, there would typically be defense wounds. Defense wounds tend to be on the hands and forearms, and to be quite severe-looking. They may look much worse than the fatal wounds. They can be distinguished from suicidal hesitation marks by their severity, and to a lesser extent, by their location and orientation along the body lines. Langer Lines (or "longers") are the natural grain of the skin. When the skin is cut, as by a knife wound, the skin pulls back the along the langer lines. If the wound is lined up with the "longers", the wound will appear to be longer than the width of the blade. If the wound is perpendicular to the longers the wound may actually be shorter than the width of the blade, and would be more evulsed.

In general, it is very difficult to determine exact dimensions for the stabbing weapon based solely on the dimensions of the wound. (The Ramsey County Medical Examiner's Office has an expert at it.) In addition to the effect of the langer lines, the orientation of the knife as it enters the skin, and the effect of twisting or rocking the blade as it enters and is withdrawn from the body, all alter the size of the wound. The length of the wound can be considerably greater than the width of the blade.

It is also not easy to tell the angle of the stab by simply examining the wound. Typically the wound is "probed" (an instrument or finger is inserted into it) by the medical examiner to get an approximate angle of penetration. However, there is no way to duplicate the exact posture of the victim at the time of the stabbing, so the internal organs and tissues are in different positions at the time of the post-mortem exam. Therefore, the angle determined by probing is only approximate.

Do not attempt to probe the wound yourself. This can alter the dimensions of the wound, and make the medical examiner's job even tougher.

Self-inflicted knife wounds....

Most self-inflicted knife wounds are attempts to gain attention for the victim, and are not fatal or even serious. Officers who have dealt with such incidents typically find relatively neat, shallow, parallel wounds. In general, suicidal wounds are similar, only more severe. However, psychotic people have occasionally cut themselves with severely painful multiple wounds.

Suicidal knife wounds frequently have hesitation marks very close by on the skin. These are caused by the knife being held poised on the skin in preparation for the actual cut or stab. They may be so close to the actual wound that they are partially obscured by the wound or the swelling around it. They are usually very superficial, and therefore not consistent with a wound inflicted by another person in a homicidal attack.


Lust murders are a type of serial murder distinguished by passionate brutality. For these killers, the murder itself is an act of sex. They typically choose victims who do not know them. If not caught, they will eventually murder another victim. Traditional methods of investigation are difficult, for lack of immediate suspects. However, such crimes share common characteristics, which has proved helpful in solving them.

The first responder to a lust murder will find a very bloody crime scene. The victim is frequently eviscerated; that is, the abdomen will be slashed open and the internal organs exposed, pulled out, or even removed. The face and genitals may be mutilated, with multiple wounds. The murder weapon is usually a knife, occasionally it is some other slashing or piercing instrument. There may be evidence of firesetting, postmortem slashing, and sadistic acts or torture. The scene of the crime may be the victim's apartment, a motel room, or an isolated or outdoor setting.

The FBI's Behavioral Science Unit (BSU) has studied many of these killers, and learned a good deal about lust murder as an abnormal behavior pattern. Abnormal behaviors follow well-defined patterns symptomatic of the psychological traits of the subject. Variations within the patterns are characteristic of the individuality of the subject. These patterns and variations are reflected at the lust murder crime scene.

Just as the average person can tell a good deal about some aspects of a person's personality, from a short conversation with him, the BSU can deduce a lot about the lust killer by examining the behavior of the killer, as indicated by the evidence at the scene of the lust murder. The BSU has provided amazingly accurate information to police departments investigating such crimes. The information has, in some cases, enabled the department to track down the killer.

In order to analyze the killer, the BSU studies the crime scene and the victim, usually through the photographs and information submitted by the investigating department. They need plenty of clear photos of the entire scene, and lots of detail shots. They need to know how the detail shots are oriented into the scene. They also need to know all about the victim; his/her or her appearance, habits, social and work behavior, clothing, and activities of the day and night of the killing.

With enough information, the BSU may be able to tell you the age, sex, work habits, social habits, family background, marital status and appearance of the killer. In some cases, they have even been able to correctly tell the police;

and other information seemingly unrelated to the crime, but very useful to the police in developing suspects and gathering evidence.