by D P Lyle
needle enters the skin. Would there be too much dilution from the IV solution already in the line? If it worked, could this look like a hospital accident if the victim was receiving treatment for dehydration, exposure, and malnourishment? Would he be getting something like potassium chloride to elevate his electrolytes anyway?
A: Absolutely Patients suffering from dehydration and malnutrition often receive IV fluids, which are typically D51/2 normal saline with 40 milliequivalents of KCL per liter. This means a liter (1000 cc) bag of saline which has half the salt (NaCl) of "normal" blood (thus "1/2 Normal Saline") to which 40 meq of potassium chloride (KC1) has been added. It is typically given at 100 to 200 cc per hour, which means the potassium is going at a rate of 4 to 8 meq per hour (40 meq in 1000 cc yields 4 meq per 100 cc).
Giving KC1 faster than 20 meq per hour is dangerous, so the above flow rate is well below that. Pushing 100 meq of KC1 intravenously is obviously way above this, and dilution is nonexistent in "IV push" administration. This dose would stop anyone's heart in seconds.
One caveat: Concentrated KC1 like this burns severely when given, so the patient/victim would react unless he was in a coma or very heavily sedated. Of course he will die quickly, but he would yell out before he fades to black because it burns that severely. Factor this into your plot, and you'll be okay.
Options: The victim could be in a coma or sedated or restrained, and the killer could hold a pillow over his face while giving the KCL. Nurses could be distracted by a Code Blue or an unruly patient at the other end of the hall. The fire alarm could be triggered to create confusion.
If Someone with Tuberculosis Is Smothered, Would There Be Blood on the Pillow?
Q: How would someone look who had been suffocated with a pillow? If the person also had tuberculosis, would the pillow have signs of blood that had been coughed up?
A:Asphyxia by pillow suffocation leaves less evidence than manual or ligature strangulation because bruises or abrasions on the neck are not present. However, asphyxiations of all types typically result in petechial hemorrhages (also called petechiae) in the conjunctivae of the eyes (the pink mucous membranes that line the eyelids and surround the eyeball). The petechiae are small bright red dots or splotches, usually pinpoint or slightly larger in size. When these are found, some form of asphyxiation is likely, and your M.E. or sleuth would determine this quickly.
In addition, most victims of asphyxia have a deep purple color to their skin, particularly the head, neck, and upper body. Also, if the victim struggles, he may bite his tongue, sometimes severely, or may have the attacker's skin and blood under his fingernails.
As far as TB goes, bleeding would be unlikely but possible. TB is an infection of the lungs caused by mycobacterium tuberculosis. This bacterium causes the formation of tubercles (also called granulomas) in the lungs. These are basically small nodules (small round lumps or clumps), microscopic to pinpoint in size, scattered throughout the lungs. They are composed of the bacteria and the various types of white blood cells sent to fight the infection. These tubercles are the body's attempt to wall off or contain the infection.
Occasionally these tubercles will caseate (break down or liquefy), and if so, they may bleed. The patient will then cough up
sputum streaked with blood. We call this hemoptysis. Rarely does the person have severe bleeding.
In your scenario the struggle for air could result in bleeding, but it would likely be streaks of blood, not overt or massive bleeding. The pillow could have streaky bloodstains on it.
THE POLICE AND THE CRIME SCENE
What Does the Wound from a Close-Range Gunshot Look Like?
Q: If a young man is shot at close range in the temple and is found within a two-hour time period, what would the wound look like? Simply a hole? Would it have bruising around it?
A: When a gun is fired, the muzzle expels more than the bullet. Burned and unburned powder residue and the hot gases produced by the detonated powder are also released (Figure 17). Each of these can alter the resulting wound pattern and may allow the medical examiner to determine the distance between the muzzle and the victim.
The anatomy of the entrance wound depends on how close the muzzle is to the skin. If it is several feet away, the entrance wound would be a small hole, smaller than the bullet due to the elastic quality of skin (Figure 18a). There would be a blue-black bruising effect in a halo around the entry point (called an "abrasion collar") and some black smudging where the skin literally wipes the bullet clean of the burned powder, grime, and oil residue it picks up during its travel down the barrel. This smudging is often easily wiped away with a wet cloth.
If the muzzle is closer, there may also be "tattooing" or stippling of the skin (Figure 18b). This is due to burned and unburned powder as well as small pieces of the bullet that are discharged from the muzzle. These tiny particles embed in the skin and/or cause tiny hemorrhages (red dots of blood within the skin) in a speckled or splattered pattern around the wound. These cannot be wiped off because the particles are actually embedded (tattooed) into the skin.
If the muzzle is held very close to the skin, the tattooing pattern is more dense and clustered near the wound since there is less distance for the bullet and powder fragments to fan out (Figure 18c). Also, there will be some charring of the skin due to the hot gases of the muzzle blast.
If the muzzle is held against the skin (contact wound), the actual entrance wound may be larger than the bullet, and the charring is likely to be worse. It will also be more ragged and irregular, and often takes on a "stellate" (starlike) pattern (Figure 18d). This is particularly true if the contact wound is over a bone such as the skull in your scenario. This is due to the explosive gases actually tearing the skin around the muzzle as they follow the path of least resistance. The expanding gases cannot expand the gun barrel or the bone, so they escape laterally by tearing through the layers of the skin.
The exit wound would be large and irregular since the bullet would pass through both sides of the skull, and typically each time a bullet strikes bone, it becomes more flattened, misshapen, or mushroomed. This leads to large, irregular exit wounds.
Follow-up Questions and Answers:
Will a Bullet Fired at Close Range Exit the Skull, and If So, Will the M.E. Be Able to Use It for Ballistic Analysis?
Q1: Whether the victim is shot at close range or from several feet away, would the bullet exit the skull?
A1: Your choice. It could or it could not. These things are very unpredictable, and either way is realistic. The physical parameters that determine whether the bullet exits the skull would include the size and weight (caliber) of the bullet, whether the bullet was a hollow point or another type, whether the bullet was jacketed with metal, Teflon, or some other durable coating, the muzzle velocity
(the speed the bullet is traveling), the thickness of the cranium (skull bone), the angle at which the bullet struck the skull, and a few other factors. A large, soft, low-speed, hollow-point bullet would be less likely to pass completely through the skull than would a small, high-velocity, Teflon-coated one.
Q2: If the bullet does exit the skull, would there be a way for the pathologist to determine what type of ammo was used?
A2: Unless the bullet was very severely damaged by the skull and the wall or whatever it embedded in, the ballistics people could probably tell the type of ammo and maybe find some rifling grooves for comparison if the weapon or other bullets from the same gun were found. On the other hand, the bullet could be so fractured, flattened, or distorted that little of use could be gleaned. If the bullet wasn't found, an experienced M.E. might be able to guess the caliber and type of ammunition used from the nature of the bullet track through the skull and brain, but a definitive answer would likely be impossible. Again, it is your choice as to whether the bullet is identifiable or not. Either is realistic.
Can Stored Blood Be Used to Stage a Death?
Q: If someone removed and stored his own blood and later used it to stage his
death, would the coroner be able to tell that the blood wasn't fresh? The scene I have in mind is a car over a cliff and into the ocean. No body would be found, but the victim's blood would be on the glass and upholstery, leading the police to conclude the body must have washed out to sea. Would the blood need a preservative to keep it from clotting? Could it
also be frozen and thawed? Would the fact that the blood was stored or thawed show up in the forensic tests? Would the salt water interfere with DNA matching?
A: The victim could remove his own blood and either use an anticoagulant (any substance that prevents blood from clotting) such as EDTA or let it clot, then refrigerate or freeze it. In a typical crime scene such as in a room or an accident on dry land, the M.E. might be able to determine if the blood had clotted beforehand by looking at the microscopic organization of the clot. Its architecture may make him suspicious that the blood had clotted before it reached the scene. For example, a large clot of blood lying on the carpet with no corona of blood soaking the carpet around it may look as though it was simply dumped there rather than bled there, which of course would be the case.
He might also be able to determine if unclotted blood had been frozen. He would look for fracturing of red blood cells, which occurs during freezing. Also, since blood clots very quickly after it leaves the body, if the M.E. found a pool of blood that hadn't clotted, he would likely conclude that some form of anticoagulant was present and thus the scene had been staged. He would then test the blood for the presence of an anticoagulant.
If the blood was flash frozen and later thawed out and dumped at the scene, where it would then clot, the M.E. would probably not be able to determine if the blood had been frozen. The clotting process itself fragments and destroys most of the red blood cells (RBCs) so that any fragmentation of the RBCs would be assumed to have occurred due to the clotting.
The M.E. might not be able to make a clear determination in any case, however.
In the scenario you describe, the car would be in the water, and probably beneath it, and this fact would change the evidence dramatically. Most of the blood would wash away so that the M.E.
would be dealing with residual stains on the seats, doors, and possibly the glass. He wouldn't expect to find clots or pools of unclotted blood in this situation. A square of the upholstery would probably be cut out and used for analysis.
He would be able to perform a DNA match since the stain would provide all the DNA he needed. The salt water wouldn't change this result.
There are two things the M.E. might find amiss that could raise his level of suspicion. One would be the bloodstain pattern. If it looked staged rather than the expected pattern in such an accident, he might question the scene. Another red flag would be an elevation of the anticoagulant EDTA in the blood, but only if he tested for it. EDTA is sometimes sprayed on vegetables in the grocery store to prolong their freshness, so we all have a trace amount in our blood. That means it would be very difficult to state that any level found in the victim was elevated. There is no normal level for comparison. Still, an excessive concentration might give him pause and give you a nice thread to follow through your story.
Would Glycerol Used as a Blood Preservative Likely Be Found in Blood Used to Stage a Crime Scene?
Q: In my story someone tampers with a crime scene by planting blood evidence from a bag of blood preserved with glycerol and then frozen. My questions are these: Does the M.E. routinely check blood obtained at a crime scene for evidence of previous freezing? Would freezing hamper DNA typing? If the blood was thawed by an amateur rather than being properly handled, would the blood have a similar appearance to fresh blood and would the presence of glycerol still be detectable even if it was not specifically being sought?
If a test was made on the sample for illegal narcotics, would the presence of glycerol be detected?
A; Blood at a crime scene is usually collected with cotton swabs, which are stored in glass vials until testing. Though microscopic examination of a liquid sample of blood might yield evidence that the blood had been frozen (ice crystal fragmentation of the red blood cells), this is not routinely done and couldn't be done from the blood collected on a swab.
DNA testing doesn't rely on intact cells, so freezing and thawing, clotting, or drying of the blood would have no effect on DNA matching.
The thawed blood, if spread around the floor or on furniture or bedsheets, would look like blood from any other source. Of course, the absence of clotting might suggest that the blood had some type of anticoagulant such as EDTA or glycerol added. This depends on how quickly the crime scene is discovered. If found immediately, any pools of blood would develop clots fairly quickly (in a matter of minutes) rather than stay liquid. If found later, these pools of blood will have clotted and will have a jellylike consistency. If they didn't clot, the M.E. would suspect the presence of an anticoagulant. If it is found even later, after the blood has dried, the M.E.'s task of determining whether the blood had clotted before drying would be difficult if not impossible.
Glycerol is an organic alcohol that has many industrial uses. It is the basic ingredient of the gums and resins used in exterior house paint and other protective coatings. It is used as an emulsifier and stabilizer in ice cream, shortening, and baked goods. It is used in the production of nitroglycerin. And relevant to your question, it is used as a protective medium for the freezing of red blood cells (to prevent the ice crystal fragmentation of the cells), sperm cells, corneas, and other living tissues.
Of course, if the M.E. tested for glycerol, he would find it, but that isn't necessarily part of a routine drug screen. Different labs
have different protocols for what they test and what they don't. This means that if it fits your story to have the glycerol not found, or vice versa, it'll work.
How Soon Do Strangulation Bruises Appear?
Q: If a person tries to strangle another, how soon would visible marks occur on the neck? What would be their nature? Would the pressure indicate whether the person was right- or left-handed?
A: The marks are basically contusions or bruises, just like those acquired when you run into a door or table. The bruising appears in a very few minutes. The seepage of blood into the tissues from damaged capillary blood vessels causes the bluish discolorations. If a victim is strangled to death, the heart stops beating, and the blood in the vessels clots fairly quickly. Once the blood has clotted, bruising is no longer possible. In other words, strangling a dead person will not leave bruises.
The bruises appear from the blood that seeps out during the strangulation, before death. It happens almost immediately, though the surface discolorations we associate with contusions may take several minutes to appear.
The typical strangulation marks are the same bluish discolorations around the neck. These marks often are very distinctive and may outline the fingers or, if it is a ligature-type strangulation, even reveal the pattern of the rope, chain, or whatever was used.
The more pressure, the more bruising. A right-handed person tends to have a stronger right hand, and vice versa for a lefty, so the M.E. might be able to determine handedness of the killer from the bruises. At least he might be able to make an educated guess, which is what a great deal of forensics is about anyway.
When Does a Decomposing Body Begin to Smell?
Q: All things being equal, roughly how long would it take for an undiscovered dead body in a home begin to smell strongly enough to attract the attention of neighbors?
A: In general, twenty-four to forty-eight hours. That's when the body would start to get ripe, and things would get worse from there.
Decomposition of dead bodies is due to two different processes. Autolysis is the aseptic (without bacteria) breakdown of the body's cells and tissues. It is due to the action of the enzymes that normally exist within the cells—sort of a "self-digestion." These are chemical reactions, and they are accelerated by heat and slowed by cold.
The second is putrefaction, which is bacterially medi
ated. The bacteria that cause this process come both from the environment and from the normal bacteria that reside in the corpse's colon. These bacteria, like the above-mentioned intracellular enzymes, prefer a warm and cozy environment. So putrefaction is also accelerated by a higher ambient temperature and slowed in a colder environment.
In your situation the corpse would begin to smell in roughly twenty-four hours or less in a bedroom in New Orleans in August; a week or longer in an unheated apartment in Chicago in January. In a more temperate climate, a day or two should do it.
Do the M.E. and Police Use Vicks VapoRub to Mask the Odor of Decomposing Bodies?
Q: What is the substance that many coroners place on their upper lip when visiting a crime scene or performing an
autopsy (presumably to offset the smell)? Does it have special properties, and, if so, can other substances (such as Vicks VapoRub) be used when it isn't available?
A: Yes, Vicks VapoRub is often used. Also, a surgical mask sprinkled with a peppermint concentrate is used by surgeons who must debride (the removal of dead and/or infected tissues) malodorous wounds such as those infected with gas gangrene (Clostridia). Trust me, the smell of this is absolutely the worst thing you can encounter. It will literally knot your stomach and make your eyes water. The peppermint helps marginally. If the debridement is extensive and takes some time to accomplish, several surgeons may work in rotation so they can spell each other every twenty minutes or so because the odor of gas gangrene is that oppressive.
When the police or the crime scene technicians must work near a decomposing corpse, they often swipe a bit of VapoRub on their upper lip to mask the smell.
Fortunately, our olfactory nerve (the nerve that connects the odor-sensing cells in the nose to the brain) fatigues quickly. This means its ability to transmit smell signals to the brain weakens as exposure to the odor continues, and thus the intensity of the odor declines. Everyone has experienced this. After a very few minutes a noxious odor becomes more tolerable, and a faint odor fades and may disappear altogether. Even the wonderful aroma of warm apple pie is most intense when first detected.
