NEWINGTON — For 40 years, the homicide case of 22-year-old Roberta Walls went unsolved.
The woman was found dead in a field behind Old Donation Elementary School in Virginia Beach, Va., on the morning of May 15, 1986. She had been stabbed multiple times and was sexually assaulted, said the Office of the Attorney General of Virginia.
Throughout the investigation, police looked into numerous people who knew Roberta and, as forensic technology advanced, compared their DNA with evidence at the crime scene…