On the morning of December 19, 1991, the body of thirty-six-year-old Kim Ancona was found in the men’s restroom of the Phoenix, Arizona, bar where she worked. She had been fatally stabbed and sexually assaulted. Her killer left behind little physical or forensic evidence. Blood at the crime scene matched Kim’s blood type, and the police didn’t perform semen or DNA tests. Investigators relied on bite marks found on Kim’s breast and neck

Shortly after the murder, the Phoenix police identified their first suspect, Ray Krone. Krone was Kim’s friend and became a regular customer at the bar. Phoenix police asked Krone to make a Styrofoam impression of his teeth for comparison. And according to the police, his teeth matched the bite mark on Kim’s body. But is a bite mark enough evidence to convict someone of first-degree murder?