10 More Horror Movie Characters Who Didn't Know They Were The Killer

Dario Argento's classic 1982 giallo Tenebrae sees a writer of horror novels, Peter Neal (Anthony Franciosa), stalked by a serial killer while on a book tour in Rome, the killer claiming to be inspired by Neal's work.

Though the single killer is initially believed to be obsessive TV interviewer Cristiano Berti (John Steiner), Berti is himself hacked to death with an axe half-way through the film.

And while Berti did indeed commit the first spate of murders, it's revealed at the end that he was killed by Neal, who after hearing about Berti's spree inspired by his books, uncovered a repressed memory from his own youth where he killed a girl who sexually humiliated him.

This memory evidently laid dormant for years until Berti's murders brought it back to the surface, driving him mad and causing him to venture on his own killing spree, leading to his own demise in the climax.