Borum resided at the Manokin Manor Nursing and Rehabilitation Center in Somerset, Maryland at the time of his disappearance. He was last seen there at approximately midnight on January 3, 2000. At 2:00 a.m. he was discovered missing from his room. A witness observed him at Mount Vernon Road and Route 13 near the nursing home at 2:30 a.m. Borum has never been heard from again. Extensive searches failed to locate him.

Borum was not dressed appropriately for the cold weather and it is believed that he may have died of exposure. There is no evidence that he is alive: he had not contacted loved ones, and there has been no activity on his health care plan and his financial accounts since his disappearance. His remains have never been located, however, and his case remains unsolved. He was declared legally dead in August 2000.