Leon was last seen on April 24, 1984, when he and a friend, William Roby, went fishing on the Connecticut River near the Route 119 bridge in Brattleboro, Vermont. Leon's father, from Hinsdale, New Hampshire, reported him missing on April 28 after they failed to return from their fishing trip. On May 7, their boat was found 30 miles downstream in Turner Falls, Massachusetts. On May 22, Roby's body was discovered 15 feet offshore, behind the Paddock Motel on Route 119 in Brattleboro. The Hinsdale Police Department in New Hampshire is the investigating agency.