Friday the 13th: Hate-Kill-Repeat is a 2005 novel written by Jason Arnopp and published by Black Flame.
Official Summary Edit
It's a psychopath showdown! This summer, Crystal Lake is twice as dangerous! Respectable-looking serial killers, Norwood and Penelope Thawn, are on a bloody crusade to purge America of sin. On the run from the FBI, the Thawns head for Crystal Lake in an attempt to make contact with Jason Voorhees, who they feel shares their moral outlook. However, the murderous juggernaut of destruction we all know and love does his best work alone and he doesn't like the competition. The scene is set for a battle royale and the unfortunates stuck in the middle had better say their prayers.
Packed full of thrills, chills and good old-fashioned slasher mayhem, Hate-Kill-Repeat proves that Jason is the top dog of monsters.
Timeline-wise, this story takes places between Friday the 13th Part VII: The New Blood and Jason Goes to Hell: The Final Friday while apparently disregarding Friday the 13th Part VIII: Jason Takes Manhattan, as reference is made in the opening to Tina Shepard's confrontation with Jason, the novel ending with the FBI apparently preparing for the sting operation that would kill Jason in Final Friday.
In contrast to the film series' 'rule' against Jason killing children, at one point during his rampage in this novel he apparently kills a family of two parents and two small children, but it could be that the children were unintended collateral damage as Jason eliminated their parents as he is not explicitly shown committing these murders even if the aftermath makes it clear that they are deceased.