If the circumstances surrounding death indicate the possibility of homicide, then the body and immediate surrounding area become crucial in estimating time of death. Time is one of the most important factors of consideration in a murder case. It may very well convict a murderer, break an alibi, or eliminate a suspect. Estimating the time of death, especially in cases where there are no witnesses, is critical to the investigation. A good homicide detective is going to want to know the time of death in order to establish a foundation for further inquiry.

Time may focus attention on various suspects. For example, the deceased may have had an appointment with someone at a specific time. In cases of "exclusive opportunity," where only certain persons are present during a specific time (e.g., husband and wife during the evening), if one of those persons is found in nightclothes the following afternoon dead from a beating, and the estimation of time of death places the incident in the range of 3 to 6 A.M., the spouse is sure to be the suspect.

A definite time of death can corroborate or disprove a suspect's alibi. Those circumstances are extremely rare — e.g., a bullet hitting and stopping a watch or an eyewitness who was present when death occurred and noted the time.

In civil matters, time may be the factor that determines whether an insurance policy was in effect or was void. Most insurance companies include "suicide clauses" in their policies whereby they are released from contract to pay if the insured commits suicide within a specific time, usually within 1 year after becoming insured. Furthermore, in probating a will, it can be crucial to learn whether the husband or wife died first because the estate usually goes to the one who expired last.

Throughout the years, forensic scientists and pathologists have searched for a definitive method of determining time of death; yet, at present, no single reliable method has been found. Moreover, because it is impossible to fix the exact time of death, we refer to an estimated time. Based on an appreciation of a large number of variables, an experienced pathologist can arrive at a reasonable estimation of time of death, usually placing it within a range of hours. The process is subject to error, especially if some crucial piece of information is omitted. It should be noted, however, that this estimation certainly represents more than just an educated guess. It is a scientifically derived opinion based on a totality of specific factors distinctive

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Figure 9.1 PUTREFACTION AND INSECT ACTIVITY. These photographs depict the body of a man in a bathtub, fully clothed and lying in the water. The cause of death was electrocution. A hair dryer was found in the tub. This event occurred indoors during the summer time. The body is in an advanced state of decomposition due to the extensive maggot activity. (From the author's files.)

to each particular case compared with ordinary time factors attributed to the pathological changes that occur in a human body.

Although the homicide investigator is not expected to have the knowledge of a forensic pathologist, he would certainly do well to have some basic understanding of the postmortem changes that occur in the human body and the effect of time and atmosphere on the cadaver, on blood pools, and on stains so that he can make intelligent observations at the scene.

I have found that it is good procedure to take notes of the appearance of the deceased and any blood at the scene so that you can relate to the medical examiner exactly what you observed. The investigator should also interview the first officers for their observations of the scene along with the exact time of their arrival. These observations will be helpful in the analysis of approximate time of death when coupled with the results of the medical examination and autopsy. Generally speaking, the sooner after death a body is found, the more accurate and precise the estimation of time of death will be. A "fresh" body gives a better time frame than one in advanced putrefaction. However, it is utterly impossible to fix the exact hour and minute that life ceased unless you were there at the moment of death. That is the reason why I stress the importance of assessing and documenting the early postmortem interval changes at the scene.

The Process of Dying

To understand what takes place in the body after death, one must first have some basic knowledge of the processes that occur in the living body. During life, the systems of the human body have the capacity to maintain themselves by providing oxygen to all the body tissues. In addition, the system provides for the removal of waste products that result from body functions. This is accomplished by the circulation of blood through the arteries and veins. The heart keeps the supply of oxygen continually flowing by its pumping action. As the blood deposits oxygen to the tissues, it picks up the waste products and returns to the lungs, where a new supply of oxygen is obtained. During this process, the body is able to defend itself from bacteria and germs within the body. Upon death, however, these bacteria grow at will and begin to release enzymes, which dissolve the internal body components. The changes that occur in the dead body are recognized as postmortem decomposition.

The body begins to decompose from the time of death in a manner dependent on any number of variables, such as temperature, time, location of the body (outdoors, indoors, in soil, in water, in the desert, etc.), humidity, air currents, physical condition, and clothing. Externally, insects and animal life may attack the remains so as to disfigure the body further. These changes in the human body result from the same process one observes in an unrefrigerated piece of meat when it rots.

Dying is a process, and estimating the time of death depends on those factors that occur during that process. Death can be said to occur in stages, and a "smart"

Figure 9.2 GROSS PUTREFACTION. The body of a man who overdosed on methadone has gone into gross decomposition. (Courtesy of Detective John Carlone, Newport, Rhode Island, Police Department.)

Figure 9.3 DECOMPOSED BODY. Note the bloating and peeling of skin. This body was indoors with the windows closed and not subject to insect infestation. (Courtesy of Dominick

J. DiMaio, M.D., former chief medical examiner, City of New York.)

Figure 9.4 PUTREFACTION. Note the bloating and decompositional blisters as well as the greenish discoloration around the area of the abdomen. This is a classic example of autolysis, the breakdown of cells and organs from the aseptic chemical process caused by interacellular enzymes. (From the author's files.)

medical examiner will want to see the scene or have proper documentation of the scene before he or she attempts to make any determination about the time of death.

Body Changes after Death

Color. Upon death, the heart ceases to function. As a result, the blood and its lifegiving properties cease to circulate through the body. As the blood settles into the dependent capillaries of the lower portions of the body, it gives the upper surfaces of the skin a waxy or translucent look. The lips and nails lose their normal pinkish or lifelike color. The blood, which has ceased to circulate, changes from a bright red to a deep purplish color as it loses oxygen. This is apparent even in persons with darker skin. This is the beginning of lividity, the process whereby the blood settles into dependent capillaries and eventually "fixes" in certain areas of the body.

Eyes. The eyes, which are the most sensitive area of the human body, do not react to light, touch, or pressure in death. The cornea or clear part of the eye becomes slightly milky or cloudy within a half-hour to several hours after death. The changes are affected by whether the eyelids are open or closed; the temperature, air currents, and humidity will also affect the condition of the eyes. In fact, to the experienced observer, the eyes alone will indicate that death has occurred.

Loss of body heat. During life, the body maintains an approximate temperature of 98.6°F. After death, the body gives off heat until it becomes the same temperature as the surrounding medium. The rate of cooling can be an important measurement in the estimation of time of death and is dependent upon a number of factors: the temperature at the time of death, the temperature of the environment, body covering and clothing, and the portion of the body in contact with the surface area. Body temperature can be taken by rectum with a thermometer to obtain an accurate reading. However, core body temperature is generally considered the most reliable indicator of time of death up to approximately 18 hours. Core body temperature is taken by inserting a thermometer into the liver, which is then compared with the ambient temperature in the crime scene.

The environmental temperature should be taken at the same time if the body temperature is to have any meaning. Never take the temperature by inserting a thermometer into a wound; when the wound was received, the body was probably standing or sitting, not lying face down or in a supine position. If a thermometer or probe is carelessly inserted into the wound, it will probably cause additional damage to the organs or tissues beneath the wound entrance or destroy or distort the wound track. In addition, in gunshot cases, it may destroy or obscure the ballistics value of a spent round lodged within the wound track. From a practical viewpoint, there are "just too damn many" variables that affect the rate of cooling, such as size and amount of fat on the body, clothing, the position of the body (bent upon itself or lying flat on surface), age of the victim, drafts, environmental humidity. It is almost impossible to calculate them all. I recommend to investigators who want to get a rough idea of just how long the body has been dead that they place the palm of their hand on a protected surface of the body, such as under the arms. If the body is warm, death occurred a few hours ago; if the body is cold and clammy, death occurred anywhere between 18 and 24 hours ago.

Rigor mortis. The process of rigor mortis is the result of a stiffening or contraction of the body muscles related to chemical changes occurring within the muscles after death. As a general rule, rigor mortis begins 2 to 4 hours after death. Contrary to popular belief, rigor mortis starts at the same time throughout the entire body; however, it is first observed in the jaws and neck. It then seems to progress in a head-to-foot direction and is complete in 8 to 12 hours after death. At this stage, the jaws, neck, torso, and upper and lower extremities are literally "stiff as a board" and, in this marked state of stiffening, resist any change in position. Rigor "fixes" the body in the position assumed at death. I had one particular case where the body of a young boy who had been brutally murdered and sodomized became literally "frozen" in the position of assault.

A body seated in a chair at death will remain in that position, with arms and legs fixed in the position of a seated individual, even after removal. This complete rigor begins to disappear about 18 to 36 hours after death and, in the average body, is completely gone within 48 to 60 hours.

Figure 9.5 RIGOR MORTIS. This young boy was found literally "frozen" in the position of assault in a South Bronx abandoned building. He had been brutally sodomized and stabbed to death. Rigor mortis has resulted in "fixing" the body in the position in which it was lying at the time of death. (From the author's files.)

Figure 9.6 RIGOR MORTIS. Victim of homicide found in rigor in this position. The body had been dumped down a ravine, where it came to rest after tumbling down the incline. (Courtesy of Lt. Mark Prach, Morris County Prosecutor's Office, Morris County, New Jersey.)

Figure 9.7 GENERAL TIME ELEMENTS INVOLVED IN RIGOR MORTIS. (Courtesy of

Medical Legal Art. Illustration copyriught 2005, Medical Legal Art, www.doereport.com.)

A word of caution: this factor is the poorest of the gauges used in estimating time of death because of the many variables involved. The various theories on rigor mortis are loaded with contradiction and misinterpretation. For example, obese people do not always develop rigor and skinny people develop it fast; heat speeds up the process of rigor and cold retains it; a fight or body shock usually accelerates it; no two bodies even under similar circumstances develop it at the same time.

Practically speaking, if the underarms are warm to touch and the body is without rigor, death probably occurred less than 3 hours earlier.

Cadaveric spasm. Under certain conditions, the stiffening of the hands or arms may take place immediately at the time of death. This is known as cadaveric spasm and is often confused with rigor mortis. It is not uncommon for persons who had a firearm or a knife in their hand at the time of death to clutch it tightly in their hands after death. Also, suicides have been known to have the weapon clutched tightly in their hands after death.

It is important from the investigator's point of view to note such clutching of weapons because you can be sure that the person held this weapon at the time of his or her death. It is impossible to "duplicate" this spasm. For example, a person attempting to place the weapon in the deceased's hand after death cannot get the same type of tight grasp. Cadaveric spasm remains until putrefaction. I have a number of cases of cadaveric spasm in my files from various jurisdictions across the United States. The reason I mention this is that some forensic pathologists do not recognize this phenomenon.

Figure 9.8 CADAVERIC SPASM. The deceased's hand tightly clutches the weapon in cadaveric spasm, which is instantaneous rigor mortis. (From the author's files.)

Figure 9.9 CADAVERIC SPASM. The deceased, who was terminally ill with cancer, used his firearm to end his life. Note the man's hand is clutched tightly on the handle of the gun and his thumb is pressed down onto the trigger. (Courtesy of Corporal Larry Hallmark, Grapevine, Texas, Police Department.)

Postmortem lividity. Also known as livor mortis, this is caused by the pooling and settling of blood within the blood vessels from the effect of gravity. It appears as a purple discoloration of the skin. During life, the pumping action of the heart maintains a constant flow of blood through the numerous vessels of the body. Upon death, this pumping action ceases, and the blood pools within the dependent portions of the body. The location of livor mortis is determined by the position of the body after death. If the body is lying face down, livor will develop on the front of the body rather than on the back. The observation of lividity is important for two reasons:

1. It gives you a general idea how long the body has been dead.

2. It tells you definitely whether or not the body was moved after death.

For example, if lividity is observed on the back of a body found lying face down, you can be sure that the body had originally been on its back. Lividity begins about 30 minutes after death, with full development after 3 to 4 hours, and becomes "fixed" in 8 to 10 hours. Fixed means that the livor has settled in one position for more than 8 hours and can no longer be significantly shifted by changing the position of the body. However, parts of the body that remain in direct contact with an object, such as the floor, a piece of pipe or wood, or even the weapon, will remain white because the pressure will not allow the blood to settle into the dependent capillaries.

When lividity first develops, if the investigator presses his finger firmly against the discolored skin, the pressure will cause "blanching." When pressure is released, the discoloration returns. After 4 or 5 hours, the discoloration becomes clotted and pressure will not cause blanching.

Figure 9.10 POSTMORTEM LIVIDITY. At the crime scene. Notice the deep purplish discoloration as well as the white pressure areas of "blanching" on the victim's back, where the body was in contact with a hard surface. This is a classic example of lividity. (From the author's files.)

Figure 9.11 POSTMORTEM LIVIDITY. Note the pinkish discoloration on the victim's back. This photo was taken at the morgue. (From the author's files.)

Figure 9.12 LIVIDITY IN BLACK MALE. Sometimes the color of the skin will mask the presence of lividity, especially in dark-skinned victims. Note the "blanch marks" on the face, shoulder, and chest where the pressure prevented the blood from settling in the dependent areas. (From the author's files.)

The investigator should know that the discoloration will not be the same for all types of death. For instance, a person whose death was caused by inhalation of carbon monoxide or cyanide or whose death occurred under extremely cold conditions will have a livor mortis that is cherry-red in color. If a person lost a great deal of blood, little or no discoloration will be seen; in cases where death was caused due to heart failure or asphyxia, a deep purple color will be present. These observations should be recorded and the coloration of the lividity evaluated with the later toxicological examination performed at autopsy.

Suppose you have a body that is cool to the touch and rigor has set in in the neck and jaws; when you press against the lividity, it does not blanch. Under ordinary conditions, you can assume that the body has been dead about 6 to 8 hours. Notice that I said ordinary conditions, and watch the word assume.

Remember: You are dealing with tricky circumstances, and even the experienced pathologist will have to weigh all the facts before he attempts an estimate.

Gastrointestinal tract contents. Although commonly referred to as stomach contents, this also includes digested and undigested matter within the entire body. The presence of food particles in the stomach and upper small intestine provides still another source of information to the pathologist regarding time of death. From an investigator's point of view, the presence of food on the table may offer some assistance if the victim maintained a routine eating time. When the deceased ate his last meal and what he ate then are important information for the pathologist who will do the autopsy.

Various ingested food materials remain within the stomach for variable periods of time, depending on the nature and size of the meal. It has been determined through extensive research that, under ordinary circumstances, the stomach empties its contents 4 to 6 hours after a meal. If, at autopsy, the stomach is found to be filled with food and digestion of the contents is not extensive, it is reasonable to assume that death followed shortly after the meal. If the stomach is entirely empty, death probably took place at least 4 to 6 hours after the last meal. If the small intestine is also empty, the probability is that death took place at least 12 or more hours after the last meal. In certain cases, the medical examiner will be able to determine the type of food still remaining in the stomach, if matched with the last known meal. This can help establish a time period.

Of course, this determination will be made by the medical examiner conducting the autopsy. I have been present at many autopsies where the stomach contents were examined and it was quite discernible what foodstuffs were ingested by the deceased prior to his death. In certain cases, it is a good procedure to obtain a control sample of the food products found at the crime scene that were apparently eaten by the deceased, for comparison with the stomach contents, especially in cases which involve the possibility of murder by poison or of suicide by ingesting toxins or deadly drugs.

Figure 9.13 GASTROINTESTINAL TRACT. (Courtesy of Medical Legal Art. Illustration copyright 2005, Medical Legal Art, www.doereport.com.)

Putrefaction. The most certain sign of death is when the body is in decomposition. Decomposition, or putrefaction, is a combination of two processes: autolysis and bacterial action. Autolysis is the breakdown of cells and organs through an aseptic chemical process caused by intracellular enzymes. Because it is a chemical process, it is accelerated by heat, slowed by cold, and stopped by freezing. Bacterial action results in the conversion of soft tissues in the body to liquids and gases. The chemicals produced as a result of putrefaction are cadaverine and butyl mercaptides as well as hydrogen sulfide and other sulfides, which generate a horrible smell.

Putrefaction begins immediately upon death and usually becomes noticeable within 24 hours. As soon as death occurs, the bacteria or microorganisms within the intestinal tract escape from the bowel into the other tissues of the body. As they grow, they begin to produce gases and other properties that distort and discolor the tissues of the body.

The discoloration is a dark greenish combination of colors and is generally pronounced within 36 hours. As a result, the body begins to swell from the putrefactive gases, emitting an extremely repugnant odor. The rate of decomposition depends on the temperature, ground conditions, amount of clothing, size of the body, etc. For example, a body in a warm climate will not only encourage insect attack from the outside, but will also increase the interior bacteria development

Figure 9.14 PUTREFACTION INDOORS. Note the bloated face of the deceased. This victim's body was found indoors during the summertime. He had been dead for only 60 hours when discovered. (From the author's files.)

and subsequent tissue attack from within. As the tissues inside are destroyed and enzymes released, the gases formed emit a foul and sickening smell.

This particular method of determining time of death is very inaccurate because of the variables involved. The putrefactive changes disfigure the facial features, making visual identification by relatives impossible. Postmortem changes may also alter the appearance of and camouflage antemortem injuries. When bloating and darkening occur, it may be difficult to determine the race and color of the deceased.

Because putrefaction, just like rigor mortis, is subject to a great variation, the estimate must be based on other sources derived from the autopsy and the scene. It has been established that even in deaths occurring as a result of the same cause, with identical environmental conditions, one body showed an advanced state of putrefaction and the other showed little change. The general signs of putrefaction are

1. Greenish discoloration of abdomen and genitals.

2. Veins in the skin are blue or purplish due to pigment of decomposing blood. This is referred to as marbling. Marbling is produced by the hemolysis of

Figure 9.15 POSTMORTEM BIRTH. Note the dead fetus between the legs of the deceased. The woman, who was 7 months pregnant, died from a heart attack. As the body began to decompose, the putrefactive gases and bloating caused the fetus to descend and the baby was expelled from the mother's womb. (Courtesy of Dr. Dominick J. DiMaio, former chief medical examiner, City of New York.) blood vessels with reaction of hemoglobin and hydrogen sulfides and development of red, purple, or greenish black discoloration along the vessels.

3. After the body fluid dries, a yellow parchment-like membrane forms.

4. After several days:

a. The abdomen swells and the body bloats (from gas).

b. Purge fluid emits from mouth and nose (the source being the lungs andstomach).

c. Rectum may empty.

d. Skin blisters resembling peeling sunburn and filled with watery fluid andputrefactive gases appear on the skin, which has darkened.

Adipocere. This is a greasy, soap-like substance which develops on the surface of a body that has been lying in a moist area, such as a swamp, or in damp soil. It is due to chemical changes that occur in the body fats — hydrogenation of body fats into fatty acids. It develops mostly in warm weather and usually forms in 6 to

Figure 9.16 MARBLING. Produced by hemolysis of blood vessels with reaction of hemoglobin and hydrogen sulfide and development of red, purple, or greenish black discoloration along the vessels. (From the author's files.)

8 weeks. The material is rancid smelling and floats in water. Adipocere usually covers the face and buttocks, but any part of the body can be affected. Where it is present, the internal organs are usually in good shape because they have been dehydrated and mummified in the process.

Mummification. The conditions that produce mummification are the exact opposite of those causing adipocere. If death occurs in a hot, dry place with an adequate and constant circulation of dry air, and body fluids are rapidly absorbed, the body tissues become hard and dry instead of decomposing. The mummification process delays putrefaction, and as a result the form of the body may be preserved for years.

External Agents of Change

Insects

Various insects may eat the flesh of, or lay eggs on, the body of the deceased. Observation of insect larvae can aid in the estimation of time of death. This is an example of the assistance that an entomologist — insect expert — can lend to the investigator. Many insects develop from eggs and then progress through growth stages before emerging as adult insects. The time element involved in this developmental stage is rather constant for any given species. For instance, the adult female

Figure 9.19 INSECT INFESTATION. This body had been subject to advanced putrefaction and insect infestation from house flies and maggots. It should be noted that an entomologist could make determinations of estimated time of death based upon a forensic evaluation of the structures and habits of certain necropagous insects collected from the carrion, which provide cycle time frames for the species. (From author's files.)

housefly deposits eggs upon the remains, usually in the mucous membranes of the eyes, mouth, and nostrils and also in the wounds and bloody parts of the body. These eggs are white, measure about 1/16 of an inch long, and are laid in clumps. The eggs develop into the larvae (maggots), which then feed off the body. The usual time span for hatching of the maggot is 24 hours. On a body lying indoors, the larvae usually come from the common housefly (Musca domestica)

Development time varies among the various species of flies. Temperature and humidity play very important roles in this developmental stage, as do other factors. The larvae may even go into a period of suspended animation if conditions do not warrant further development.

The bluebottle, or blowfly (Calliphora erythrocephala), greenbottles (Lucilia caesar), and sheep maggot flies (Lucilia sericata) are the most common types found on remains discovered outdoors. The investigator at the scene and the medical examiner at the autopsy should collect some specimens for examination by an entomologist. The entomologist can identify the specific insect and provide an estimated time frame based on the stage of growth or development of the larvae. In addition, the experienced entomologist can possibly identify the stage of the life cycle and, ultimately, the season of the year in which death occurred.

In order to assist the entomologist in making an accurate determination, the following procedure for collection and preservation of specimens is recommended:

Figure 9.20 INSECT ACTIVITY. The most common insects to invade the human body after death are flies. The common housefly and the outdoor bluebottle are seen more frequently than some of the others. This photo shows flies on a body. The flies lay their eggs and the developing maggots feed off the remains. The entomologist can assist in this phase. (Courtesy of Detective Mark Czworniak, Chicago Police Department.)

1. Collect some maggots from the remains and place them in a KAAD solution. (This is a mixture of kerosene and alcohol along with certain other ingredients for preservation.) If this solution is not available, place the sample in hot water first, then in a bottle containing alcohol, and then seal it. The hot water bath will prevent the alcohol from shriveling the sample and maintain the specimen in a condition for examination.

2. Collect some live maggots as a control sample and place them in a separate container.

3. Collect any pupae (hard, shell-like casings or cocoons) from around the site, under the body, and the corpse. Keep the samples separated. The presence of pupae usually provides a minimum time span of approximately 2 weeks. However, several cycles may be involved, and the determination should be left up to the entomologist.

Note that the type of maggots found on the body may be significant. For example, the presence of larvae from a housefly found on a body outdoors will indicate that the body had previously lain indoors.

In addition to flies and maggots, a body is also subject to insect attack from different types of beetles that feed off the body (called carrion beetles) as well as ants and even worms that bore their way into the body. These are among a vast

Figure 9.21 PUPAE. Hard, shell-like casings or cocoons. (Courtesy of Detective Mark Czworniak, Chicago Police Department.)

host of scavengers responsible for recycling decaying materials. The recommended procedure for collecting all insect samples is to place them in 75% ethyl alcohol for preservation.

The forensic entomologist has knowledge of many of the habits of insects and other invertebrates most likely encountered on the corpse and/or in the immediate surroundings of the scene. Seemingly insignificant data to the untrained eye, such as insects not found on the body, habitat information, and climatological conditions, can be observed by the entomologist. This knowledge enables him to form certain determinations and opinions of how long the body has been at the scene.

In keeping with the team concept of homicide investigation, I recommend that an entomologist, if available, be brought to the scene to assist the investigators. The entomologist's expertise will ensure that proper entomological techniques are employed and the collection of specimens is conducted as it should be.

Plants

Bodies found lying on the ground are usually in areas that are abundant with plant life. A competent botanist can estimate the age of vegetation found under the body in relation to the vegetation found in the immediate surrounding area. Samples of the sod and vegetation found under the body, as well as a control sample from the immediate area, should be collected for examination.

Remember: Keep the two samples in separate containers to prevent any cross-contamination.

The botanist can then examine these samples and may be able to determine how long the body has lain in a particular location. Although this information will not provide an estimate of time of death, it can contribute a relevant time factor to the investigation.

Animals

Bodies are also subject to animal feeding, indoors as well as outdoors. Animals feed off the remains of a dead human body just as they feed off any other piece of meat.

Household pets as well as rats and other rodents often attack the body in indoor locations. I investigated one scene in which the deceased's dogs had actually begun to devour the body. Outside locations increase the chances of this occurrence because many wildlife creatures are carnivorous. Ravens, crows, seagulls, and turkey buzzards are just a few of the carrion birds that will feed off a body and may leave wounds that could be initially mistaken as mutilation injuries consistent with some sort of assault. I remember conferring with authorities in a Florida case where turkey buzzards had fed off a woman's body before police recovered it. The turkey buzzards had eaten the eyes and around the eye sockets. The authorities at first thought that the offender had taken the eyes until they conferred with their medical examiner, who recognized the damage as having been caused by the buzzards.

Figure 9.22 POSTMORTEM ANIMAL FEEDING. Bodies are also subject to animal feeding indoors and outdoors. This woman's face was eaten by the family dog, which increased putrefactive changes to the internal components of the body. You can also observe skin slippage on the woman's scalp as her hair separates from the skull. (From the author's files.)

Figure 9.23 ANIMAL FEEDING. This badly burned body had been dumped at an outside location where animals fed on the cadaver. (Courtesy of Dr. Leslie I. Lukash, chief medical examiner, Nassau County, New York.)

Bodies that have been mutilated by domestic and wildlife creatures or insect activity may give an appearance of gross injury, which is not necessarily associated with an antemortem attack. In addition, certain portions of the body may have been carried away or be missing from the cadaver due to animal activity. Practically speaking, investigators must be careful not to jump to any false conclusions based on their initial observations at scenes of this type.

Bodies in Water

Similarly, marine life, especially crabs and/or lobsters, are known to nibble on "floaters" (bodies in the water). Many different forms of marine life, including lampreys and eels, may invade and/or feed off a human body submerged in the waters. In addition, movements of the currents and/or contact with marine propellers will further add to disfigurement. These types of postmortem injuries require the knowledge and interpretation of the forensic pathologist so as not to be mistaken for an injury that occurred in life.

From an investigative point of view, a body exposed to the air for 1 week is equivalent to a body submerged in water for a 2-week period. A body in water generally decomposes more slowly due to the colder temperatures as well as the lack of oxygen. However, a body disposed in a septic tank or in waters containing large amounts of chemcial waste or bacteria will cause decomposition to be accelerated. The following are some general time spans associated with bodies in water:

• Hands swollen after several days

• Outer layer of skin separated from the body within 5 to 6 days, skin of the hands and fingernails separated from the body in 8 to 10 days

(A)

(B)

Figure 9.24 BLOATED BODIES OF "FLOATERS." (A) Male body. (B) Female body. Notice the effects of submersion and postmortem changes in the tissue. Both bodies had been in the water for approximately 1 week. Many times it is difficult to determine the sex of bodies which have been immersed in water. (From the author's files.)

• Seaweed vegetation on the body within 8 to 10 days

• Floating — in warm water, 8 to 10 days; in cold water, 2 to 3 weeks

Information Derived from the Scene

Even though certain morphological changes in the body after death are subject to measurement, the variables involved require additional supportive information before an estimate of time of death can be made. Data obtained by the investigator relative to events associated with the deceased are of utmost importance. This is where the work of the homicide detective really comes into play. I have been involved in many homicide investigations where the determination of the approximate time of death was directly related to the information retrieved from the crime scene and the neighborhood canvass. (See "The Canvass" in Chapter 4.)

The date and time the deceased was last seen alive give the detective a starting point to begin the task of narrowing the time of death. The status of the deceased's home or apartment lends additional information — e.g., are there any current newspapers, milk deliveries, mail in the mailbox, dishes in the sink, food on the table? Are the electric lights on or off? If the lights are burned out, is the light switch in an on or off position? Are the shades drawn or open?

The detective will want to reconstruct the deceased's last known movements. These would include who spoke to him or her last and where the deceased was prior to being found (at home, at work, with a friend, etc.). The failure of the deceased to perform a daily routine, such as picking up the newspaper, reporting for work, jogging, calling friends or family, or any other personal habit which was routine in his or her life, will also help narrow the time frame.

Another factor to be considered is the weather. For example, if the deceased is found outdoors covered with snow and the ground beneath is dry, it is important to know what time the snow started in the area. It would be safe to assume that the body was on the ground before the snow fell.

In cases where there has been a struggle and the deceased has a broken watch or a clock in the room has been damaged, causing it to stop, the time of death can be pinpointed if the investigator can ascertain whether the timepiece was in working order prior to death and kept correct time.

Remember: The presence of prepared food on the table may offer assistance in determining time of death if the investigator can ascertain that the victim maintained a routine eating time.

Information derived from the scene as well as knowledge of any personal habits of the deceased will play an important part in the final estimate of time of death.

These are referred to as associative factors.

Conclusion

The estimate of time of death is complex. Before you lock yourself into a specific time frame, it is imperative that all the information available be examined by competent experts. If the time of death tends to fix responsibility for the death or becomes the factor that points the finger at a particular suspect, then the estimate must be based on positive facts and interpreted by the experienced pathologist.

The physical manifestations of death discussed in this chapter, as well as the autopsy findings; the deceased's personal habits; the medical opinion regarding survival interval, the period between the infliction of injury and death; and the statements of witnesses, must be taken into consideration in the final analysis. Therefore, complete cooperation between the experienced homicide investigator and the medical examiner/coroner is essential if there is to be an intelligent estimate of time of death.

Remember: Do it right the first time. You only get one chance.

Selected Reading

Deickman, E.A. Practical Homicide Investigation. Springfield, IL: Charles C Thomas, 1961.

DiMaio, D.J. and V.J. DiMaio. Forensic Pathology. 2nd ed. Boca Raton, FL: CRC Press, 2001.

Geberth, V.J. Practical Homicide Investigation: Tactics, Procedures, and Forensic Techniques. 3rd ed. Boca Raton, FL: CRC Press, 1996.

Spits, W. and R. Fisher. Medicolegal Investigation of Death. Springfield, IL: Charles C Thomas, 1993.