DNA evidence both convicted and eventually freed Amanda KnoxOli Scarff/Getty Images

The Secrets of Our DNA

Turi King

UK, Doubleday; US, Transworld Digital

In 1993, a 62-year-old woman in the town of Idar-Oberstein in Germany was found strangled with florist wire. DNA found on a coffee cup suggested that two people were present besides the victim and that one of the apparent killers was a woman.