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by Murder

  Certain gangs boast their own tattoos. In California the CAL-GANG database stores such data, and often a query will result in a hit. This type of lead may result in the ultimate identification of the victim.

  Can the Age of Surgical Scars Aid in Victim Identification?

  Q: My protagonist is a detective who is confronted with a female corpse whose hands and head have been removed to hinder identification. She has a scar on her abdomen, which he believes is about three months old. This is important because a woman of about the same age and size was reported missing, and she had had her gallbladder removed three months before her disappearance. Can the age of scars be determined this accurately?

  A: Yes and no. Any wound, whether surgical or from a knife fight, will follow the same healing pattern if it is closed properly with sutures and doesn't get infected. Lack of proper treatment or an infection of the wound would lead to delayed healing and more prominent scarring. Also, some people develop keloids when such wounds heal. A keloid is a raised thick scar that can be a half inch wide and rise a quarter inch above the surrounding tissue—sometimes more.

  With normal healing the wound becomes mechanically strong after about two weeks. For several weeks the scar will be slightly pink to brownish red due to the microscopic blood vessels that invade the area to aid with the healing process. Over the next few months, as the body repairs the damage by laying down collagen (thick fibrous strands of connective tissue), the color gradually fades, and the scar shrinks considerably. With further maturing of the scar it finally becomes a faint white line by four to six months. The collagen continues to shrink until about one year. Thereafter, the scar remains unchanged for life. This means that the age of a scar can be approximated in the first four to six months, but after that all bets are off.

  Your astute detective could see a 6-inch diagonally directed wound in the right upper quadrant of the corpse's abdomen and construe that it was from a cholecystectomy (gallbladder removal). He could further see that it appeared well healed but still possessed a pinkish hue and deduce that the wound was likely between six weeks and four months old. This would at least leave open the possibility that the missing woman and the corpse were one and the same. However, dental records, DNA evidence, or some other form of identification would be necessary to determine the true identity of the victim.

  Will Stomach Contents Reveal When and What the Victim Ingested?

  Q: My murder victim is found in the middle of the night. I have two questions. First, for a high-profile case, would the autopsy be done early the next morning? Second, can the autopsy tell very specifically what the victim ate? For example, if the victim ate chicken, vegetables, and bread five to six hours before death, would the contents still be visible at the time of the autopsy? Also, can the autopsy determine specific fluids and drugs, such as Coca-Cola versus tea or aspirin versus Alka-Seltzer? Would it be logical for a medical examiner to find traces of bicarbonate of soda and aspirin if the victim took Alka-Seltzer shortly before death?

  A: Yes, the autopsy could be done the next morning. The M.E. could simply juggle the day's schedule and handle the high-profile case first. Also, in many jurisdictions the M.E.'s office has a "special cases room" where "special case" postmortem examinations can be videotaped.

  Stomach and intestinal contents found at autopsy depend on

  several factors such as the type and amount of foods consumed and the time lapse between ingestion and death. Digestive processes cease at death. Various foods remain in the stomach for different amounts of time. In general the stomach empties by four to six hours and the small intestines by twelve hours. If food material is found in the stomach, it would be reasonable for the M.E. to determine that death likely occurred within four hours of the meal. If the stomach is empty, he might conclude that the victim ate more than six hours before death.

  Partially digested food, either in the stomach or in the small intestine, might reveal what that last meal was. This would be particularly true for high-cellulose foods such as corn since the body cannot digest cellulose. The vegetables in your scenario may still be identifiable, especially if you shorten the time between eating and death to less than four hours.

  The stomach contents, blood, and urine would be tested for drugs. Unless death occurred shordy after ingestion, finding Coke or tea and distinguishing aspirin from Alka-Seltzer would be difficult.

  Aspirin is acetylsalicylic acid (ASA), which is also in Alka-Seltzer (which also contains sodium bicarbonate and citric acid). Once ASA is in the bloodstream, it would be impossible to tell what ASA-containing product it came from unless undigested pills were present in the stomach. This is unlikely with Alka-Seltzer and aspirin since both dissolve readily.

  Coke is simply sugar syrup, colorings and flavorings, caffeine, and carbonated water, all of which are digested and absorbed into the bloodstream fairly quickly. Most teas also contain caffeine.

  Bicarbonate is a normal electrolyte in blood, so unless a large amount of Alka-Seltzer was ingested, it would be difficult to trace after digestion.

  The M.E. could easily detect ASA, which is invariably part of a routine drug screen, and caffeine. Finding abnormal levels of bicarbonate would be more difficult and much less specific.

  A complete examination of the crime scene could help the M.E.

  here. If food was still on the table or in the refrigerator, it would help him analyze the stomach contents by narrowing his focus. The same would be true if aspirin and Alka-Seltzer bottles were found. The M.E. uses all the evidence he can accumulate, not just the autopsy, drug screen, and so forth, in making his assessment of cause and manner of death.

  Can the Type of Alcohol Found in Stomach Contents Be Determined?

  Q: In my story an old woman with a fondness for wine is found shortly after death in the tub of her stiflingly hot trailer. Would chemical analysis during an autopsy show what kind of alcohol the woman was drinking? Although she is known to drink only wine, a glass with a small amount of whiskey in it is found on the edge of the tub. Also, if distinctions between whiskey and wine can be detected, could an analysis also determine the brand of the whiskey? Would an autopsy show that the woman was actually drunk or only that she did indeed have alcohol in her system?

  A: The M.E. might be able to determine the type of alcohol consumed if the victim expired shortly after drinking it. Since digestive processes cease at death, the stomach contents stay more or less intact. Decay and bacterial-mediated putrefaction would alter them over time, and these processes are accelerated in a warm environment. But this process might take a couple of days or more in most circumstances. If the stomach contents were well preserved, it might be possible to determine the type and even the brand of the alcohol.

  If the alcohol was consumed a couple of hours or more before death, the digestive process would be fairly complete, since alcohol

  is basically a type of sugar and digests readily. The stomach contents probably would not be helpful, and once alcohol is in the bloodstream, it is alcohol. Blood analysis could distinguish ethanol (ethyl alcohol, the type in alcoholic beverages) from methanol (methyl alcohol, which is denatured alcohol, a poison) from iso-propanol (isopropyl alcohol, which is rubbing alcohol), but if ethanol is found, it is generic ethanol; that is, in the bloodstream, wine is like vodka is like a good sour mash whiskey.

  The blood alcohol level can be readily determined, and it is this level that dictates legal intoxication. In California the legal limit is 0.08 milligrams of alcohol per 100 milliliters of blood. This varies from state to state. Some people—and this seems more prevalent in women than in men—can become impaired at lower levels. Everyone is different. The M.E. could determine the blood alcohol level, and even if it was below the legal limit, he might be able to make a good guess as to the victim's level of impairment.

  Can an Autopsy Reveal a History of Pregnancy or Childbirth?

  Q: If a female corpse is autopsied soon after death, can the pathologist tell if she has had child
ren or been pregnant? What if the body is partially decomposed from several months' exposure to cold weather?

  A: After pregnancy there are permanent changes in the microscopic architecture of the breast and uterine tissues, which the M.E. would see. Also after pregnancy, pale striations often appear over the surface of the breasts and abdomen. These are similar in appearance to stretch marks and may have a faint pinkish, bluish, or silvery hue. Whether these tissue clues would help in your scenario depends on how well preserved the body is. The cold weather may help in this regard by delaying corpse putrefaction and decomposition.

  Even in skeletonized remains, evidence of the trauma caused by previous childbirth is often present. Multiple pregnancies and deliveries make this evidence more profound. The M.E. would look for scars on the pubic bone that result from tears of the periosteum (the layer of tissue that covers the bones) and at the insertion sites of the various tendons that attach to the pelvic bones. It wouldn't be possible to determine how many children she had delivered, only that she had had at least one.

  Can the Coroner Determine the Caliber of a Bullet by Simple Inspection?

  Q: If an M.E. recovers a bullet during an autopsy, can he determine the millimeter gauge of the bullet, or would ballistics determine that?

  A: Both. The M.E. could make a guess as to the type of bullet, but confirmation would require a true ballistics exam. Depending on how much damage the bullet suffered, an experienced M.E. could tell a .38 slug from a .45 from a 30.06, and some are very good at it. A complete ballistics evaluation would follow to confirm this and to make the information more acceptable in court.

  In Slashing Wounds, Can the M.E. Determine What Weapon Was Used?

  Q: I have a victim of a slashing being autopsied. How would I describe the wound if it is from a sharp claw versus a sharp instrument? How would the medical examiner know that the wound was caused by something other than a knife?

  A: In general, slashing or cutting wounds are extremely difficult to analyze. Determining the type of weapon is virtually impossible. With stab wounds you have depth, width, thickness, angle of attack, shape of the blade, and sometimes serrations that help determine what type of weapon was used. These same characteristics make comparison with a suspected weapon easier.

  With slashing wounds these characteristics don't exist. A Bowie knife and a dagger make very different stab wounds but similar slash wounds simply because the nature of the slashing motion produces a long wound with ragged edges that bleeds considerably.

  A claw or talon could make a similar wound. The pathologist might be able to determine the width and at least a minimum length of the object by the depth and width of the wound, but little else unless trace evidence (fur, talon fragments, tissue, attacker's blood) was left behind.

  Can the Coroner Distinguish Between Freshwater and Saltwater Drowning?

  Q: In my story an elderly man with early-stage Alzheimer's is found floating in a bay, but he was actually drowned earlier in a backyard swimming pool. Would chlorine from the pool show up in the man's system during autopsy? Because the victim is initially presumed to have drowned in the bay, would the medical examiner expect to find debris, such as small bits of vegetation or the like, in his lungs? What would the M.E. be looking for in a drowning situation like this?

  A: In drownings the M.E. can determine if it was freshwater or salt water and should be able to determine if the water contained

  chlorine. This freshwater versus salt water distinction was used in the movie Chinatown.

  To understand the differences between freshwater and saltwater drownings, let's first take up the issue of osmosis. Osmosis is the passage of a liquid through a semipermeable membrane driven by a concentration gradient. Simple, huh? Let me explain. We use the term "tonicity" to describe the concentration of electrolytes (sodium, potassium, chloride, and so forth) in a liquid. The major electrolyte in the human body and in the blood is salt or sodium chloride (NaCl). "Isotonic" means the liquid has the same tonicity or NaCl concentration as blood. If the tonicity is less, as in fresh or pool water, it is termed hypotonic ("hypo" means lower or less). If the tonicity is higher, as in salt water, which contains a higher concentration of salt than blood, it is called hypertonic ("hyper" means above or more).

  For our discussion a semipermeable membrane is a barrier that allows water to pass through but not other molecules such as sodium chloride. Water moves across this barrier from the hypotonic (lower concentration) liquid toward the hypertonic (higher concentration) liquid (Figure 19a). This movement continues until the tonicity on each side of the membrane is the same. In reality the water molecules continue to move back and forth, but once the tonicity is equal, the movement of water in each direction is equal. Think of it as the relatively hypertonic liquid acting like a sponge that "pulls" water toward it. Once things balance on each side of the membrane, this sponge effect is lost.

  The tissues of the lungs are semipermeable membranes designed to allow oxygen and carbon dioxide free movement back and forth. The blood that bathes the lung tissue is isotonic.

  In a freshwater drowning (Figure 19b), hypotonic fluid is introduced into the lungs. This causes water to move from the water-filled air sacs of the lungs into the bloodstream. This occurs because the isotonic blood is actually hypertonic relative to the hypotonic freshwater. This movement of water dilutes the blood,

  making it hypotonic relative to what it should be. In a saltwater drowning (Figure 19c), the opposite occurs. Salt water is hypertonic relative to blood, so water moves out of the bloodstream and into the air sacs of the lungs.

  The M.E. would examine the lungs and the blood of the victim. In a freshwater drowning he would expect to see relatively dry air sacs (the water has moved into the bloodstream) and diluted or hypotonic blood. In a saltwater drowning he would expect to see wet air sacs (the water moves from the blood toward the salt-water-filled lung tissue) and concentrated or hypertonic blood. If he didn't find what was expected, he might conclude the body had been moved. It is important to note that this process of water movement doesn't happen instantly, so if the victim is pulled from the water quickly, little change may be detectable on these exams.

  In your scenario the M.E. could find evidence for freshwater drowning and could find the lungs contained some residual chlorinated water. He would deduce that the victim had drowned in a swimming pool and not in a saltwater bay.

  Yes, the victim's mouth, throat, and even his lungs could contain debris, vegetation, algae, and even small aquatic creatures, which would be those found in the area of drowning. There would be a mismatch if the body was moved to a different location after death. This was used in the film Silence of the Lambs when the larvae found in the throat of one victim was that of a rare moth that wasn't indigenous to the United States. The same can be said for vegetation. Of course, in a swimming pool the victim would probably not aspirate any vegetation or debris. If he drowned in a pond or lake, then freshwater vegetation or bugs rather than chlorine would be the findings that cause the M.E. concern. Here the M.E. would state that the victim was moved because the drowning was freshwater and the vegetation and bugs were freshwater life forms; thus, the victim could not have drowned in the saltwater bay.

  Will an Autopsy Determine If Chlorine Is Present in the Lungs?

  Q: I know the M.E. can determine whether a drowning is freshwater or salt water, but can chlorine be detected in a drowning victim and lead to the conclusion that the drowning occurred in a pool rather than a bathtub?

  A: Yes. Samples of the lung tissue and any liquid that the lungs contain can be tested for chlorine. Some labs have to send the samples away to a more sophisticated lab for analysis, but the chlorine can be detected in most cases.

  Do Skin and Nail Changes Occur with Some Poisons?

  Q: I've read that some poisons can be determined by examining the skin and fingernails of the victim. Is this true? Do you have any examples of which poisons can be detected this way?

  A: Yes.
Many poisons cause changes in the skin, hair, mucous membranes of the mouth, and nails.

  Lead: Chronic lead poisoning (plumbism) has been around for many centuries and may have led the decline of the Roman and Greek empires. Today it usually comes from exposure to lead-containing paints, gasoline, and plumbing pipes, and cooking or eating from ceramic containers that are finished with lead-containing glazes. Plumbism is associated with anemia, headache, abdominal pain, joint pain, fatigue, memory problems, neuropathies (weakness and/or numbness in an extremity), and a blue-black line at the junction of the teeth with the gums, called a "lead line."

  Mercury: In children mercury poisoning can cause a syndrome known as acrodynia or pink disease. It is characterized by flushing, itching, swelling, excessive salivation and sweating, weakness, red, irregular skin rashes, and scaling of the skin on the palms and feet.

  Arsenic: Chronic exposure to arsenic can cause hyperkeratosis and hyperpigmentation (thickening and darkening) of the skin, exfoliative dermatitis (flaking and sloughing of the skin), and transverse white lines in the fingernails, called Mee's Lines. Arsenic can be detected in the hair of victims of chronic poisoning.

  Cyanide: Cyanide is a metabolic poison in that it blocks cytochrome oxidase, an enzyme found in the mitochondria of the cells. The mitochondria are responsible for cellular energy production and oxygen utilization. Blocking cytochrome oxidase prevents the cells from using oxygen, resulting in their death.

  Cyanide forms cyanmethhemoglobin through a complex interaction with the hemoglobin found in the red blood cells, which lends a bright cherry red color to the blood. Because of this it can be confused with carbon monoxide poisoning (see below).

  Hypostasis (lividity) is the postmortem settling of blood in dependent areas due to gravity. Typically, this is blue-gray or purple in color. With cyanide poisoning the cyanmethhemoglobin imparts a reddish hue to the settling blood so that dependent lividity in this situation takes on a brick red or dark pink color.