Many authors have written medieval murder mysteries, including me! In The Irish Bride, my latest medieval mystery, a monk is found dead within moments of Gwen and Gareth’s arrival in Ireland. As medieval detectives, how do they go about finding the killer? What can they possibly determine forensically without laboratories, fingerprints, and all the trappings of modern investigations?
Medieval forensics was primitive, but there were some things a medieval detective could determine, including time of death, whether poison was involved, and whether the body was moved (thanks to another author, Jeri Westerson, for some of this information):
Time of death: Rigor mortis—literally, “death stiffness,” happens very predictably. Beginning two hours after death and starting from the face and moving down the body, the body takes eight to twelve hours to become completely stiff, remains rigid for the next eighteen hours, and then reverses the process with another twelve hours for the body to gradually unstiffen. A medieval detective could understand that heat might quicken the process while cold might slow it.
What a medieval detective would not know is why rigor happens, but modern forensic scientists can answer that question: the body becomes stiff as a result of the body no longer being able to fight off the natural bacteria all humans carry in their system. Once a person is dead, these bacteria generate a chemical reaction that prevents the muscles from contracting.
The Greeks and Egyptians had their own system:
Warm and not stiff: Not dead more than a few hours.
Warm and stiff: Dead between a two and a half day.
Cold and stiff: Dead between a half day and two days.
Cold and not stiff: Dead more than two days.
Another aspect of dead body that a medieval detective could notice is livor mortis or lividity—basically the state of being blue. This happens because blood stops flowing and, thanks to gravity, pools in the vessels at the lowest point. Wherever the body was in contact with the floor, for example, the skin becomes pale and ringed by lividity. Lividity appears a few minutes to a few hours after death and stays fixed after 8 hours. “The detective would know if a body had been moved if lividity had set in on the wrong part of the body.” http://workingstiffs.blogspot.com/2009/09/more-medieval-forensics-part-two.html
Poisons: In my mystery series, Gareth and Gwen encounter many poisons. Fortunately, most of the most common leave some kind of trace, and these include Belladonna, Hemlock, Monkshood/Wolfbane, and Foxglove.
Blood spatter: Certain aspect of medieval forensics involve close observation of the remains. Did the dead man die where he lay? Which way did the blood flow? Was he stabbed in the heart, meaning he knew his victim, or was he killed from behind with a garrote or a blade?
More commonly, then as well as now, deaths were caused by people who knew their victim. In small communities in the Middle Ages, individuals close to the dead person would come under immediate suspicion, and unless the person was killed by an arrow, a murderer would have had to have close contact with the victim in order to kill him.
Likely also, the the murder rate was far higher in those days than it is today.
“It’s hard to know the true homicide rate because reporting wasn’t as accurate in those days and crime-solving was basic and often unreliable. But we do know that violent crime was a far bigger problem in Medieval times than it is now. For example, the number of murders per 100,000 people in 1995 to 1997 in London was 2.1. But according to one historian, it would have been about 12 murders per 100,000 people in Fourteenth Century England.” [The National Archives]
Certainly, there would have been plenty of murders to keep our medieval investigator busy!