Drop of blood leads to arrest eight years after crime

CLAYTON, Mo. -- St. Louis County police believe they've solved a violent crime that occurred more than eight years ago, thanks to a drop of blood.

Lawrence Mitchell of St. Louis faces charges for robbing and sexually assaulting a woman in 1999. The 38-year-old suspect was arrested Tuesday.

Police say the victim fought her attacker, biting the suspect so hard it drew blood. That turned out to be vital to the case.

About a year ago, the blood sample was entered into a DNA index system. That eventually led police to Mitchell, who was on probation for another crime.