Cole was last seen in Fillmore, California on May 1, 1965. He had moved from San Diego, California to stay with his half-brother, David LaFever, in Fillmore earlier that year. He was still looking for a job when he disappeared. He has never been heard from again.

David and his wife, Margaret, were arrested in Arizona in 1983. They were charged with multiple counts of child abuse and child pornography in connection with an 11-year-old girl who posed as their daughter, but wasn't actually related to them. After the arrest, investigators discovered David had told friends and family members he murdered Cole.

Margaret's 20-year-old brother, Jon Brian Skaggs, disappeared in 1977. His body was found in a shallow grave near the LaFevers' former home in Galt, California in July 1984. He had been shot to death. Investigators named David as the prime suspect in Skaggs's murder and Cole's disappearance, but neither of the LaFevers were charged in connection with either case.

Cole's disappearance remains unsolved. Foul play is suspected.