Polite Dissent

Green Arrow #51 “The Return of Anarky”
James Peaty, writer
Eric Battle, penciler

Following the trail of some bank robbers, Green Arrow and Anarky stumble upon a dead body in an apartment.

Anarky: Rigor’s set in, he’s been dead for at least a day.

Anarky may be right — but if so, it’s nothing more than pure luck. His science and understanding of rigor mortis is flawed.

Under normal conditions, rigor mortis starts 3-4 hours after death with the facial muscles and then spreads to rest of the body. Full rigidity sets in at about 12 hours. Depending on conditions, rigor mortis lasts for 24-72 hours.

Cold conditions slow down the process, warm condition speed it up.

To understand how rigor mortis works requires a very basic understanding of calcium ions and muscle cells: The concentration of calcium ions is higher in the fluid surrounding muscle cells than inside the cells themselves. Nature likes concentrations to be equal, so calcium slowly leaks into the muscle cells. These increasing levels of calcium ions inside the muscle cells cause the muscle to contract. To counteract this and allow the muscles to relax, calcium is pumped out of the cells using adenosine triphosphate (ATP) to provide energy for the pump. After death, the supply of ATP quickly runs out and calcium begins to build up in the muscle cells. This leads the muscles to contract and become rigid because there is no way to pump the calcium back out. This is what causes rigor mortis. Eventually digestive enzymes within the cells become active and start breaking down proteins. This leads to a softening of the muscles and breaks the rigor mortis.

Anarky usually hangs out in Gotham City, so he probably learned his bad science from Batman.

---

Why don’t comic book detectives ever mention algor mortis or livor mortis?

Algor mortis is the cooling of the body that occurs after death. It is a slow, steady decline until the body reaches temperature room temperature. The body’s temperature can be used to indicate the time of death, though environmental factors can affect the result.

Livor mortis is the discoloration of the body that occurs as the blood settles to the lower areas of the body following death. This can also be used to suggest the time of death.