Pittsburgh police have arrested a black man accused of raping and strangling a woman to death before setting her body on fire

Police charged Nathan Henry Williams, 29, with homicide, rape, abuse of a corpse and involuntary deviate sexual intercourse in connection with the death of Elaina Davis, 57. Residents who use the parking lot on Our Way in Uptown found Davis' burned, nude body. Forensic investigators collected DNA found on Davis and entered it into CODIS, a national database of DNA samples, according to a criminal complaint filed against Williams. The DNA matched Williams', whose DNA was submitted to the database by the Allegheny County Adult Probation Office as a condition of his probation, the complaint said. Williams was sentenced to two years probation when he pleaded guilty to a simple assault charge in February 2011. Police arrested Williams and he is lodged in the Allegheny County Jail.