Once the heart stops beating, whether due to homicide or natural causes, the body enters the first stage of death. Blood drains from the capillaries to the larger veins in the parts of the body, closest to the ground. This process is called livor mortis (embalmers call it “postmortem stain”). The overall skin, once pink and full of color due to oxygen-laden blood, is now pallid, except for deep purplish-red bands where the corpse touches the ground. Think gravity.
At the livor mortis stage, the blood is “unfixed.” Meaning, a killer could throw off police by posing the victim, causing different lividity patterns. Livor mortis peaks at eight to twelve hours after death. This is when the lividity patterns are the most pronounced.
After a few hours, the pooled blood no longer moves. The livor mortis is now “fixed.” Meaning, no matter how the body is posed after livor mortis fixes, the lividity patterns will show how the corpse was originally positioned. “After livor mortis fixes” are the keywords. These purplish-red patterns aid investigators in determining possible scenarios. Under the right circumstances, it can also be the killer’s undoing. The way to test if livor mortis is fixed is to press on the areas where the blood pooled. If the skin “blanches” — meaning, turns white — the livor mortis remains unfixed. Death investigators can use that window to help approximate TOD (Time of Death).
When the heart stops beating, all muscles relax, including the sphincter muscles, which is why investigators often find remnants of defecation and urination, as disgusting as that sounds.
The process of the muscles releasing is called “primary flaccidity”. After which, they begin to stiffen — known as rigor mortis; pronounced Rye-gor (cop shows get that wrong too. Just sayin’) — which occurs within two to six hours after death due to the depletion of the muscle’s energy containers (ATP-ADP) and coagulation of muscle proteins. While alive, when adenosine triphosphate (ATP) is used it becomes adenosine diphosphate (ADP). When both ATP and ADP drain from the deceased rigor mortis sets in, starting in the eyelids, neck, and jaw. Over the next four to six hours, rigor mortis spreads throughout the body, affecting the joints of the extremities first, then the extremities themselves, then traveling inward, stiffening every muscle, including organs like the heart.
The onset of rigor mortis depends on numerous factors, including whether the victim did anything strenuous before death, like running for their lives. In all fairness, they’d have to overexert for this to affect the rate of rigor mortis. A sinister game where the killer tracks and hunts his human prey through wooden terrain, hiking up mountainsides, paddling across waterways and crawling inside deserted animal caves, over the course of several days? That’ll do it. Age, sex, build, physical condition, as well as outside factors also play a role in how fast rigor mortis occurs. Much of it depends on how fast the body cools — a process called algor mortis.
I’ve touched on algor mortis before. See Blood, Bodies, and Bugs for more info. When no muscular control exists within the body the skin succumbs to gravity, forming new shapes, accentuating prominent bones. The body then begins to cool (algor mortis).
Conditions that affect algor mortis…
- Environmental temperature. For example, if a body is found outside in the cold weather, the corpse will cool faster than if it was found inside a heated room.
- The size of the victim will affect the cooling rate. For example, a petite woman cools faster than an obese man.
- The victim’s clothes can either speed up or slow down the cooling process. A heavily-clad corpse cools slower than a scantily-clad or nude victim.
- Ventilation is a biggie. A room that’s well-ventilated could actually speed up the rate of cooling by increasing the rate of evaporation.
- Humidity plays a role, too. A body dumped in a humid location — for example, a Louisiana killing field — will cool slower than a corpse in a hot, dry climate.
- Insulation. Meaning, a body wrapped in plastic, or any other material or substance, including excess body fat, cools slower than a corpse left in the open.
- Surface temperature also affects the cooling rate. A body laid on a hot surface will cool at a slower rate than one found on an icy sidewalk, for example.
After the corpse has been stiff for twenty-four to forty-eight hours, the muscles relax and secondary laxity — also called “secondary flaccidity” — occurs in the same order, usually. First the eyelids, neck, and jaw. The length of time rigor mortis lasts also depends on multiple factors, especially ambient temperature (the air around the corpse). Infants and child corpses might not exhibit perceptible rigor mortis due to their smaller muscle mass.
The best way to asses a body’s core temperature is with a tympanic membrane (eardrum), liver, or rectal thermometer. A rectal thermometer might not be the way to go, because it’s not only difficult to use but could potentially cause postmortem injury. Could you use this as a way to show another mistake in the long line of errors by a rookie coroner? Absolutely.
I’ve also delved into putrefaction before. See What Happens at the Body Farm?
Around the second or third day after death, a greenish skin discoloration starts on the right lower abdomen. The discoloration spreads over the entire abdomen, then to the chest and upper thighs. It’s at this point when the wretched stench arrives. Sulphur-containing intestinal gas and a breakdown of red blood cells produce the discoloration and the putrid aroma. Bacteria, normally residing in the body to aid our immune system, contributes to putrefaction — commonly known as decomposition — after death.
Not only does this bacteria give the body an unmistakable odor, but it bloats the corpse, turns the skin green to purple to black and causes the tongue and eyes to protrude from their orifices and often, can thrust the intestines through vaginal and rectal openings. The natural gas also causes rank bloodstained fluid to seep out the nose, mouth, and other orifices. If someone dies from a bacterial infection, marked putrefaction could occur as quickly as nine to twelve hours after death. Need a quicker time-frame for your story? Mention that the victim suffered with a bacterial infection for days/weeks before death. Or use a drug addict for a victim (see Garry Rodgers’ comment for why).
By day seven, much of the body is discolored with giant blood-tinged blisters. The skin loosens, the top layer slipping off the bone in sheets — called skin slippage. The internal organs and fatty tissue decay contributes to the rankness. By week two, the abdomen, scrotum, breasts, and tongue swell and the eyes bulge from the sockets. This is when the bloody fluid seeps from the eyes, nose, and mouth, as mentioned above.
After three to four weeks, the hair, nails, and teeth loosen and swollen internal organs begin to rupture. They eventually liquefy. However, organs decompose at different rates. In fact, a resistant uterus or prostate could still be in tact after twelve months, believe it or not. Need your coroner to easily identify a corpse’s sex? Use this tidbit in your next story. If there’s nothing left but bones, refer to my post about skeletal differences.
Unless the corpse is refrigerated, kept below 32 degrees Fahrenheit, body cells will die. This process is called necrosis, which we’ll dive into at another time.
Now get off the computer and have some fun. For those of you who plan to watch the Superbowl, enjoy the game. Go Pats!