Warren was last seen in Toms River, New Jersey on August 7, 1983. He told his wife he was going for his daily walk along the dirt path to Ocean City College and would be back in about an hour. A security guard saw him on College Drive at 9:15 a.m., and he spoke to a jogger on Brokaw Boulevard at 9:50 a.m. He never returned from his walk and has never been heard from again. Warren's wife became alarmed when he missed a 10:00 a.m. pool party and notified police of his disappearance at 11:00 a.m. Tracker dogs traced Warren's scent to a pond off Hooper Avenue, then along the edge of a wooded area and roadway, but they lost the scent about a mile from Ocean City College.

Warren had recently retired from his position as an associate professor of engineering at Ocean County College in 1983. Prior to his employment at the college, he had worked as an engineer for Nash Controls and designed some machines used in military weaponry. There was speculation that this work had lead to his disappearance, but investigators found no evidence to support this theory.

Authorities believe Warren disappeared under suspicious circumstances. He had been married for 47 years at the time of his disappearance, and his wife stated he would always tell someone if he thought he was going to be late. He was a very athletic man and a regular jogger until arthritis in his hip forced him to curtail his exercise regime. His case remains unsolved.