In the days before fingerprints and CCTV, people had all sorts of strange ways of finding a criminal. One of the strangest was called the "bahr recht" (bier right). If someone has been murdered, you bring the suspect to the body and force him or her to touch the wounds. If they start to bleed, the suspect is guilty. This practice was common in England, Scotland, Wales, and perhaps other places during the 17th and 18th centuries.
One case in the English Coroner's Court from 1623 provides some interesting details. A woman had been found dead in her Hertfordshire home with her throat cut and a bloody knife stuck into the floor of her room. At first the court ruled it a suicide, but then changed its mind, exhumed the body, and made the dead woman's husband, mother-in-law, sister-in-law, and another relation touch it. The court records that,
. . .the brow of the dead which before was of a livid and carrion colour, begun to have a dew or gentle sweat arise upon it, which increased by degrees till the sweat ran down in drops on the face. The brow turned to a lively and fresh colour, and the deceased opened one of her eyes and shut it again; and this opening the eye was done three several times. She likewise thrust out the ring or marriage finger three times and pulled it in again, and the finger dropped blood from it. . .
Three of the suspects, including the husband, were eventually found guilty.
This little gem came from The Flying Sorcerer by Francis X King, published by Mandrake.