Now, this Jason Voorhees supposedly drowned at camp Crystal Lake back in 1957 when he was 11 years old. The counselors weren't watching him, then they made the mistake of killing his mother. The legend has it that Jason kept returning from his grave to punish whoever returned to the camp. I think we're dealing with a copycat here.
Deputy Stubbs tells the kids who the killer is that the saw at the cornfield and killed their classmates.