In large part, when autopsies appear on screen they're fairly clean in how they look. A dead body lies on the table as someone in a lab coat tells a grizzled cop something like "she's got blood under her fingernails, indicating a struggle" before moving on to ask the cop about his love life and whether he's getting enough sleep.
Autopsies, as you'd expect, are a lot messier than that and involve a lot more slicing of flesh and scooping out organs than portrayed. Here are a few things you might not know about autopsies as they occur now and have occurred throughout history.
For centuries, religious views prevented doctors from opening up cadavers, even to figure out the function of organs. Until the 14th century, messing around with corpses for medicine was outlawed entirely in the UK (where it carried on regardless) and dissection was only allowed on hanged criminals until the mid-1700s. This was a problem if you were a doctor who needed to learn how bodies work, and an even bigger issue if you chose to specialize in necks.
Inevitably, a dark industry of organized grave robbers sprung up. By the late 18th century, there was a huge black market in corpses. Gangs of grave robbers supplied anatomists with corpse after corpse, only slowing down when they wanted to control the supply in order to keep the prices up.
It got out of hand pretty quickly. Shakespeare's grave even spared a line to ward off potential grave robbers, reading "cursed be he that moves my bones" instead of, for instance, mentioning his wife, and he didn't even die during the grave-robbing heyday.
Two body-snatchers in Edinburgh, William Burke and William Hare, killed 16 people in order to sell their bodies to anatomists.
When autopsies took place, they were not as scientific as they are today. For instance, reports of an autopsy that took place in 1314 on conjoined twins noted the organs were thoroughly documented, but the reason the autopsy had been commissioned was to discover whether they had two souls or just the one.
In the 17th century, Antonio Maria Valsalva used to taste fluids from corpses to document them. "Gangrenous pus does not taste good," he wrote, "leaving the tongue tingling unpleasantly for the better part of the day".
Once we started doing autopsies, we learned a lot
Autopsies aren't just used for criminal investigations; they are also useful in determining where medical interventions went wrong.
In 1912 for instance, Richard Cabot analyzed autopsies and found "a goodly number of 'classic' time-honored mistakes in diagnosis" of diseases. To a doctor who criticized him for being too pessimistic, he wrote:
"When he has had three thousand clinical diagnoses criticized at autopsy by an independent and unprejudiced pathologist who makes full bacteriologic and histologic examinations of every case, he will find, I believe, that the facts are not less unpleasant than I have stated them to be.
He will know that his most scrupulous and careful examination of the precordia often fails to reveal acute pericarditis when it is present; that his examination of the urine will not always distinguish either acute or chronic nephritis from other conditions resembling them, and that mitral stenosis and aortic stenosis are sometimes overlooked by the best diagnosticians."
Nowadays, the first part of the autopsy is a careful inspection of the body and clothes. The body is measured, weighed (just like when you were born), and the clothing is recorded, before it's removed to inspect the external parts of the body. They may check for anything from gunshot residue to other deposits such as soil, as well as take a close look at any injuries sustained.
The poop search
Worse than the weigh-in, the dead body is sometimes put through the poop search known as "running the bowels", in which they cut down the length of the small and large intestines to see what lies inside. Poop can contain all kinds of clues about how the person died, as well as narrow the time of death by looking at digestive enzymes.
Shortly after death, a body becomes a party for ravenous microbes. Without an immune system to keep them in line, gut bacteria begin to digest the body's intestines. Once it's broken free, it will do the same for any surrounding tissue, living off chemicals that have leaked out of damaged cells. Still hungry, they'll head on to digest the liver first, before spreading to the heart and brain.
As grim as this is, it does help forensic scientists figure out when the person died. Bacteria spreads to the liver around 20 hours after death. Bad news: The person is digesting themself. Good news: We can tell it was around 58 hours ago because the person has begun to digest every organ the team tested.
For fresher corpses, you can narrow it down even further by looking in the bowels.
The food you eat generally stays in your stomach for around 4-6 hours before heading on its journey to the toilet. This means that if any of the food in the bowel is recognizably still food, it was probably eaten pretty shortly before death. As Atlas Obscura reported, an undigested french fry found in the stomach of one robber who was killed in 2012 during his crime led to the arrest of his accomplice, when they realized it was a fry from Wendy's. Investigators went to a nearby Wendy's and looked at their surveillance footage, where they managed to track the partner in crime.
Putting the bits back in
After the autopsy is over, the body is put back together again and ready for cremation or burial, depending on the deceased's wishes. Any organs that need to be retained as evidence may be kept, but likely the others will be placed in bags to prevent any leakage, before being placed back inside the body.
Before shutting the body back up again, they will often line the body with cotton wool, again to prevent spillage of bodily fluids. I did say it wasn't pretty.