 Medical legal autopsies are often straightforward, requiring only that the pathologists proceed in a careful, thorough, and systematic manner. But you will also encounter many cases that are not what they at first appear. The apparent homicide victim may really have died a suicide, or of natural causes. A murderer may move his victim's body and stage a convincing accident scene. A baby who seems to have died in an accidental fall may really be the victim of battering. Often the pathologist is the only one who can discover the facts that reveal the true cause and manner of death. To do this accurately, you must be able to recognize and identify wounds and wound characteristics of varying types. This film presents information that will aid you in these determinations. In the case of gunshot wounds, you will often be able to determine the approximate range and sometimes even the direction of fire, which may be essential to forming an opinion on homicide, suicide, or accident. When a gun is fired, the projectile, gun smoke, which contains soot, and still burning and unburned grains of gunpowder are forced out of the muzzle. The effects and patterns formed by these components provide valuable clues for determining the range from which the weapon was fired. Range is divided into the categories of contact, close range, and distance. When the muzzle is held in tight contact with the skin, the soot and gunpowder are driven into a pocket that forms between the skin and bone. None is seen on the surface. The expanding gases force the skin outward against the muzzle of the weapon, leaving the characteristic muzzle imprint seen in contact wounds. This imprint often matches the muzzle of the weapon, as shown here. In all caliber, tight contact wounds appear as round defects surrounded by the muzzle imprint. A large caliber weapon fired in tight contact often results in so much pressure beneath the skin that the expanding gases tear the skin in a star-shaped pattern around the defect. Then the stellate tearing, and here the imprint of both the muzzle and recoil spring guide are left on the wound. Blood, hair, tissue, or fabric may be found in the barrel of the weapon due to muzzle blast and negative pressure after firing. Again, note the stellate tear, the muzzle imprint, and the absence of gunpowder or soot. However, that a contact wound with the weapon held loosely against the skin results in a small amount of soot immediately surrounding the wound. Close range wounds are those close enough to leave soot deposits or gunpowder residue around the wound. Very close range, 2 to 6 inches for a handgun, may show both soot deposits and gunpowder stippling or tattooing. Slightly farther away, 6 to 18 inches will show gunpowder residue but no soot. A rifle can leave gunpowder residue at distances up to several feet. A distant shot is one which leaves no residue of powder or soot. You must be aware, however, that clothing or hair may block the effect of the burning gunpowder and lead to false conclusions. The precise variation of wound and surrounding deposits with distance depends upon the particular weapon and ammunition used. This should be determined by test firings. Determination of range of a distant shot, however, cannot be made from the wound or test firing since there is no way of determining distance beyond the range of soot and gunpowder deposits. Be aware of possible confusion between a distant shot with no visible residues and a tight contact wound in which residues have been driven into the wound and do not appear on the surface. This distinction can be made by a careful layer-wise dissection of the tissues all along the missile's path. Soot or gunpowder may be evident. Here on the meninges, the periosteum for the bone. Unless powder residue is found, a contact wound may be mistaken for a distant shot and a suicide labeled a homicide. When a gun is fired against clothing, expanding gases returning through the defect may cause the fibers to turn outward, giving it the misleading appearance of an exit wound. Soot may appear on the outside or inside of the clothing. A flat ring corresponding to the profile of the muzzle is sometimes seen. Again, a close range shot is defined as one fired from a distance such that gunpowder residue is deposited around the bullet hole. As already mentioned, the wound may also have soot around it if the gun was fairly close to the skin. Or maybe free of soot if the gun was somewhat farther away. The nature of a wound frequently yields valuable information about the direction of fire. The first problem in this regard is to distinguish between the entrance and exit wounds. The wound itself consists of a defect, the bullet hole, surrounded by a ring of abrasion caused by the scraping action of the bullet as it forces its way through the skin. This marginal abrasion can often yield valuable information about the angle of fire and allow distinction between entrance and exit wounds. An entrance wound is usually round and regular with a margin of abrasion. It is frequently smaller than the exit wound. However, you should be aware that caliber of the bullet cannot be accurately estimated from the size of the wound. An entrance wound is sometimes identifiable by fibers of clothing carried into the wound by the bullet, shown here by microscopic examination of the bullet path. Dirt and lubricant from the bullet may appear around the wound, or a ring of dirt and lubricant may occur on the clothing around the entrance wound. However, the so-called ring of dirt can sometimes be confused with soot. The ring of dirt is sharply outlined, while soot is darker at the center, fading toward the periphery. If unsure, scrape off some of the material and send it to the crime lab for examination. On occasion, you may see an entrance wound that has an irregular, bizarre shape. This results from a deformed bullet, for example one that has deflected or ricocheted from another object. A bullet can also be deformed by its passage through an intermediate target such as glass or a wall. Most often, however, the irregular shape characterizes the exit wound. It is often larger than the entrance wound. Exit wounds usually lack the marginal abrasion ring characteristic of the entrance wounds. The exception is a short exit wound, caused by a firm object being in contact with the skin at this point. The object may be a brazier or girdle, or perhaps the victim was leaning against a wall or piece of furniture. The skin is crushed between the firm object and the pressure produced by the bullet, causing this marginal abrasion. Confusion can result when there are more exit holes than entrance holes. The extra holes may be due to bullet fragments, a bullet that has split or fragments of bone. While this occurs most often in the head, this example was caused by a bullet hitting a rib. Wounds to the scalp are often readily identified. The internal surface of the entrance wound shows a characteristic beveling. A similar beveling occurs at the exit wound, but on the external surface. Again, the most common pattern of exit wound is the irregular shape. Clues to the direction of fire may be revealed by the shape of the abrasion. When a bullet strikes the body at an acute angle, an area of abrasion around the wound shows the direction of travel. Here's another example. A circular abrasion indicates that the bullet entered at more or less right angles to the body. As a point of procedure, when there are multiple wounds, the best way to avoid later confusion is to number or letter each of the entrance wounds. Then describe all of the other information in terms of the associated entrance wound, internal damage, track and exit wound, all related to the entrance wound. When you come to write the protocol, you will describe the path and effects of each bullet separately. Unless you organize the information clearly during the autopsy, the task of protocol writing becomes very difficult. Wounds produced by shotguns have characteristics similar to other gunshot wounds with some important differences. This is due primarily to the multiple projectile nature of the ammunition and its large explosive charge. Components of the shotgun shell include gunpowder, wadding material, either paper or plastic, and shot of various sizes ranging from small bird shot to larger buck shot to large single projectile slugs. In newer shells, plastic wads may extend and surround the shot to control its dispersion characteristics. When fired, wadding is expelled along with the shot, gunpowder and soot. The destructive effect can be tremendous. This is a suicidal contact wound in which the muzzle of a shotgun was placed in the mouth. A contact shotgun wound appears as a large circular defect. The abrasion sometime seen is caused by stretching of the skin due to blowback, an abrasion, as it was forced against the clothing by the tremendous pressure. This close range wound shows that the shot was beginning to spread somewhat, but still entered en masse, producing a large irregular defect with scalloped edges. This is called a cookie cutter effect. Gunpowder stippling is evident and may appear in wounds at a greater range than with handguns. Note the large abrasion to the lower left of the defect. This was caused by the impact of the wad material and can occur up to a distance of 20 feet. At greater distances, as the shot disperses, satellite wounds caused by straying shot accompanied the main defect. Each exhibits the characteristics of individual gunshot wounds including the marginal abrasion. Distant shotgun wounds show an even greater distribution pattern. Test firings can reproduce these patterns to determine approximate range. But a word of caution. An intermediate target, a door, a panel or even a window will cause premature spread of the shot. Now let's consider blunt force wounds. Those produced by objects having relatively broad surfaces. These may be of three types. In a contusion, the skin is not broken. There is hemorrhage into or beneath the skin. In an abrasion, the skin is straight with superficial layers removed. In a laceration, the skin has been torn as a result of a blunt trauma. A contusion is produced by a blow or squeeze that crushes the soft tissues, rupturing blood vessels without breaking the skin. You cannot reliably judge either the intensity of force used or the size of the object producing the trauma, since the bruise is frequently larger than the object used. It is important to be aware that a blow strong enough to produce internal damage does not always cause external contusion. The absence of contusion is not a certain indication that there is no internal damage. Wounds of this type, with two parallel contusions, are usually the result of blows with a rod, stick or whip. Each blow produces two parallel linear hemorrhages, a couple of items about contusions that could lead to misinterpretation. A chronic alcoholic may have many contusions from falls while intoxicated that bear no direct relationship to death. Different ages of the various bruises are an indication of long-standing repetitive trauma. Unlike a contusion, an abrasion can reveal a good deal about the object that caused it. This, for example, resulted from a fall on gravel. These patterned square abrasions are the result of blows from the flat end of this weapon. A roofing hammer. These abrasions from fingernail scratches. The patterned abrasions on this man's face were caused by the tread pattern of a sneaker or a running shoe. It may be difficult to determine whether an abrasion occurred before or after death. Bleeding, when present, is usually a sign of anti-mortem injury. However, if post-mortem levidity has occurred in the area of the wound, a post-mortem abrasion that tears blood vessels in the same area could also produce bleeding. A laceration is a tear produced by blunt trauma. Two types are commonly seen. The laceration caused by a perpendicular blow with a relatively broad object. And the laceration due to a glancing blow. Lacerations on the skin usually have jagged, irregular edges with abrasion around the margins. Vessels and nerves are often seen bridging the wound. Material from the weapons such as paint or rust may be found in the wound. And tissue and blood may remain on the weapon. Valuable evidence may be found by careful examination of laceration and a suspected weapon. Undercutting and shelving can serve to indicate the direction of the blow. In this case, the blow was landed in the direction shown. Sometimes it is possible to get an idea of whether a laceration of the scalp was caused by a fall or from a blow by an assailant. In general, an injury received in a fall is located at the level of the brim of the hat, whereas an injury from a blow is located above this level. Also, you should be aware that internal organs may suffer severe laceration, even when there is little or no evidence of external injury. In this case, there was no external sign of injury, but the abdominal cavity was filled with blood due to a laceration of the mesentery of the small intestine. Before we leave the topic of blunt force, one final item. Blunt force injury to the head with subsequent contusion of the brain. The significant point is that injury from a blow produces what is referred to as a coup injury and results in contusion of the brain on the same side as the blow. But injury from a fall produces a contra-coup injury, creating contusions of the brain on the opposite side of the impact. An exception is in the case of a fall against a sharp or pointed object, which may also cause coup injuries. We now turn to the subject of sharp force wounds. Again, these are distinguished in two categories. The incised wound, which is longer than it is deep. And the stab wound, which is deeper than it is long. The distinction between a blunt force and a sharp force injury is not always immediately clear. Here's how you can tell. A sharp instrument produces a straight, clean wound, usually not abraded or undermined. In contrast, the laceration from a blunt weapon is jagged and irregular. It commonly has abraded edges, undermined margins, and is bridged by soft tissue. Examination of an incised wound does not tell much about the weapon. The blade is often drawn through, creating a wound that is longer than the blade width. In a stab wound, the wounded track may be longer than the blade, because the body is compressible. These stab wounds should not be probed except under direct vision after opening the body. Otherwise, you may produce a false track and draw an erroneous conclusion. About the only thing you can determine with any reliability is the blade thickness. The wound can be held together briefly for photography and measuring for an estimate of thickness. Some stab wounds do reveal information of particular interest, however. The hilt of a knife can produce an abrasion if the blade goes in all the way. Here, the notch at the end of the blade has caused a definite impression. Wounds on hands or forearms, referred to as defense wounds, most often occur when the victim has tried to fend off the assailant's blows. An irregular wound may result from a twisting of the blade, either by the assailant or by movements of the victim during a scuffle. This can lead to confusion about the type of weapon used. So-called hesitation wounds are characteristic of suicide cuts, as numerous ineffectual attempts are made to cut deeply. In fact, suicide cuts are rarely deep, although they may appear so until examined thoroughly. This may help distinguish between suicide and homicide. In the autopsy of a victim of sharp force injuries, obtain x-rays if there is any indication that a portion of the weapon may have broken off in the body. Examination of the clothing of a victim of sharp force injuries is very important. Sometimes the holes in clothing are more valuable for determining the type of weapon than examination of the wounds on the body. Our discussion of asphyxia will cover hanging, strangulation and suffocation. For insurance, embarrassment for other reasons, victims of suicide by hanging are sometimes cut down by members of the family before the police are called. However, identification of death by hanging is usually possible for the knowledgeable pathologist. Incidentally, the victim need not be suspended for death to occur. He can be upright, semi-reclining or even with feet lightly on the floor. Vascular occlusion is all that is required to produce death. The hanging victim usually has a groove or fur around the neck. This may, however, be absent in some cases. For example, if a soft towel was used or if decomposition has begun. The marks travel upward toward the knot. This distinction of direction can be important in separating hanging from ligature strangulation. Another distinction is that in hanging, injury to the neck, muscles and bones is not usual. The face of the hanging victim may be dusky, purple and congested, with eyes frequently protuberant and firmer than usual. The tongue frequently protrudes and bloody mucus may exude from the nose. This should not be mistaken for evidence of foul play. Particular hemorrhages of the face and eyes are results of asphyxia and do not extend below the level of the noose. Tardew spots or particular hemorrhages in the lower extremities may be present in hanging cases due to settling of the blood. It's important to maintain the noose as evidence and for comparison with the wounds during autopsy. Do not cut the noose at the knot, cut elsewhere and tie back together with string or wire. If necessary, tie a wire around the knot to keep it from unraveling. Strangulation may be either manual or by ligature. Manual strangulation, throttling, is a compression or constriction of neck structures by hands, arms, legs or fixed object. Although not present in every case, a good indication of throttling is the presence of fingernail marks on the neck. There may be few or no external signs of trauma. The fingernail marks are usually seen as thin, linear, crescent abrasions. Although the shapes and positions may tend to suggest the way in which the hand was applied, no inference should be drawn. There are too many variables to determine this on the basis of fingernail marks. Neck marks may become more visible after a few hours of drying. Sometimes a single small area of bruising in a muscle of the neck is the only indication of throttling. This may only be revealed by a method of dissection that provides a dry field and avoids creating artifactual hemorrhages. Do the neck dissection last after removal of the trunk organs and brain? Fractures of the larynx or hyoid are common, but may be minute and difficult to recognize. Those fractured during life are always surrounded by a focal hemorrhage, allowing you to distinguish them from post-mortem artifacts. A sexual motive should be considered when manual strangulation is involved and the victim should be closely examined for appropriate signs. Ligature strangulation rarely occurs as a motive suicide, but it may be impossible to determine with certainty from examination of the body alone. The construction of the noose or knot and the number of turns may be helpful in forming an opinion. Fracture of the larynx, however, is a valuable finding. It does not occur in suicide. As distinguished from a hanging victim, the mark on the neck is usually horizontal and below the level of the thyroid cartilage. Also, the hyoid bone and thyroid cartilage may be fractured in strangulation but not usually in hanging. The presence of nail marks does not necessarily indicate homicide. They may be self-inflicted in a reflex action to preserve life as in a suicidal hanging. Sex associated asphyxia or autoerotic death is a form of accidental asphyxia involving sexual perversion. The victim, almost always a male, is usually found in a locked room, in his own home or a motel, or in a secluded outdoor area. Due to the bizarre circumstances, foul play is often suspected. For example, hands and feet may be securely bound. A binding which is often padded is fastened about the throat or head is covered, either leading to accidental asphyxia. Apparently, this constriction is intended to heighten sexual excitement. Erotic materials are sometimes found nearby within sight of the victim. Female attire may be present or worn by the victim, and contrary to expectation, the genitals may not be exposed. This type of death, although infrequently seen, is worth noting because of its unusual nature. The final category of asphyxia is suffocation, obstruction of the external air passages either by smothering or choking. Smothering is the mechanical obstruction of nose and mouth. When homicidal smothering is suspected, examine the insides of the cheeks, hemorrhages and tears of mucosa by forceful closure and pressure against the teeth may be the only indications of trauma. Accidental smothering can result from glue sniffing, aerosol sniffing or the like. If the substance is sniffed from a plastic bag, death may result from lack of oxygen. Abnormal rhythm of the heart is another possible cause of death when toxic fumes are inhaled. Findings will be confirmed by toxicological results. Collect samples of all body fluids and tissues and enclose each in an airtight container. To prevent evaporation of volatile substances, blood should be placed in a clean, closed test tube or vacutainer and not opened until time of analysis. Choking is the mechanical obstruction of the air passages by foreign material that is aspirated. The foreign material can be a large piece of poorly chewed food obstructing the larynx. Known as the café coronary, it most often occurs to the heavily intoxicated or the mentally deficient. Our final topic deals with the battered child syndrome. Typically, the child is between two months and five years old. Although battered children occur at every level of society, it's more common at lower economic levels and among younger parents. In the autopsy, you will want to obtain good photographic coverage of all injuries. This is very important for documentation. Also, you will record the height, weight and state of nutrition, hydration and cleanliness as indications of the parental care. Multiple fractures in different stages of healing is a recognized pattern. Obtain total body x-rays from which a radiologist can assist in aging the fractures. You may find injuries of any type including abrasions, contusions, lacerations and burns. Fractures of the ribs, humerus and femur are common. Most common are head injuries, in particular skull fractures and subdural hematomas. Often there are multiple rib fractures, usually posterior. These are unlikely to have been caused by a fall, an auto accident or the like. However, severe trauma may have been inflicted without significant injury to the skin. One sign of this is a markedly swollen abdomen. There may be lacerations of internal organs, such as the liver, spleen or small bowel. The most reliable indication of child abuse is the severe contradiction that generally exists between the appearance of the injuries and the explanation offered to explain them. Thus the pathologist plays a crucial role in these cases. The medical legal autopsy frequently presents intriguing complexities that can offer a fascinating challenge even to the highly experienced pathologist.