The popular image that most people have of Jason is of a man in a hockey mask who uses a machete to kill people. But while Jason does kill at least 6 people (Scott, Mark, Terri (possibly), Andy, Debbie and Ali) with a machete in 2 and 3, he doesn't start using the machete regularly as his main weapon of choice until he comes back to life in Part VI. In this film, Jason is the one who gets killed by a machete. Which is probably why he starts using one after his resurrection; he remembers how effective it was on him as a killing weapon, so why not use one himself?
Rob comes to Crystal Lake to get revenge on Jason for the murder of his sister Sandra who was killed in part 2. He gets killed almost immediately after confronting Jason. Now their parents have lost two children.
As most people know, this movie takes place only a day after Part III, which itself takes place a day after Part 2. That being said, Jason killed well over thirty people single-handedly over the course of only a few short days. That's most than any known serial killer has done in such a short time span in real life.
