The Tarrant County medical examiner's office has ruled the death of a man a homicide after he died of complications from a shooting 35 years before.

Craig Buford lived a normal life after recovering from a 1973 shooting by another teenager over a gambling dispute in Denver.

The medical examiner's office says the 54-year-old man's Dec. 29 death was caused by multiple organ failure. He was hospitalized a few days before his death, and doctors determined his colon had ruptured. He underwent surgery before he died.

Buford's mother, Mary Benson, says she thought the man who shot her son received probation in a plea agreement. A Denver police spokesman says he couldn't find a resolution of the case but probably wouldn't be able to comment because it involved juveniles.

Officials say homicide rulings in such cases are rare but not unprecedented. David Gunby's 2001 death was ruled a homicide caused by complications from a gunshot wound he received in the 1966 University of Texas Tower shootings.

By the time Charles Whitman was shot and killed by authorities on the tower's observation deck, 16 people had died. Gunby was among the 31 others wounded.