Corrected entry: Throughout the movie, Mel Gibson uses a New York accent. His character is supposed to be a native Bostonian.
Corrected entry: When Thomas Craven (Gibson) pulls up to Northmoor, he asks for "John" Bennett, but Danny Huston's character introduces himself as Jack Bennett only moments later. The character is in fact Jack Bennett. (00:37:15)
Correction: Jack is a nickname for John, like Bill for William or Bob for Robert, etc.
Correction: Not so - I think whoever wrote this is not sure of either accent, but it sounds good enough to me.