As many of you know Harry Oakes was one of the big names in Niagara Falls 70 years ago. There are many things in the city named after him, and his family still operates the attractions and hotels on the south side of Clifton Hill (HOCO stands for Harry Oakes COmpany). The original Harry Oakes was murdered in the Bahamas, and no one was ever convicted of his murder.
Apparently the FBI was involved in the investigation, and the FBI web site has 3 PDFs you can download with information on their investigation.
The FBI conducted an investigation into the death of Sir Harry Oakes. Initially, it was thought that Sir Oakes was murdered by a member of his family in Nassau, Bahamas, sometime in August of 1943. The FBI learned, from a source who knew Sir Oakes, advised that Oakes was found dead from natural causes in his apartment on July 23, 1943. Sir Oakes’s nephew was charged with his supposed murder, but was not convicted.