Twelve-year-old Delvacchio and his grandfather, Isley McCullough were last seen on April 28, 1973 in Gadsen County, Florida at 3:00pm in a taxicab with two other unidentified African-American male passengers in their early 20's. His grandfather operated a taxi service in the area.
At 6:00pm that night, Isley's 1973 Chevrolet was found abandoned behind the Old Bethel AME Church on High Road. There were smears of human blood inside the car and the money box (which contained $450) was in the trunk, but it was empty. There was also a spent bullet imbedded in the front seat, but there were no sign of Delvacchio or Isley at the scene, and they haven't been seen since.
Two days after their disappearance, Delvacchio's undershirt, a small wooden club and a ball-peen hammer were found neatly piled under a tree on the old Belyeu property near the bridge. After this was discovered, an extensive search of Delvacchio and Isley was mounted. A witness reported seeing two Caucasian men in the area where the car was found, but this sighting hasn't been confirmed.
Many of the witnesses in Delvacchio and his grandfather's disappearance have died since 1973 and much of the evidence has been misplaced.
Investigators believe that Isley was hauling sugar for moonshine bootleggers in the area in 1973. Isley allegedly got into an argument with a moonshiner and threatened to tell the police about his activities, but was threatened with death if he did. The moonshiner's still was raided and Delvacchio & Isley vanished the following day.
None of the information has been confirmed and it hasn't been established that it was connected to the disappearances. Foul play is suspected in Delvacchio and Isley's case and police are investigating it as a homicide. Their cases remain unsolved.