There’s a circular argument when it comes to horror films as bad influences on people. While most of the SJW’s out there will claim that horror films degrade society and cause violence, writers/directors and other horror aficionados will argue the opposite. That horror films are influenced by real life. For example, Psycho & The Texas Chainsaw Massacre were influenced by serial killer Ed Gein.
In some cases though, it’s been proven that horror films do cause some seriously disturbed people, to do some disgusting stuff. These guys here, are the worst of humanity. Whether they’re just fucked up, or the movies fucked them up, is up to the legal experts to decide.
That said, you can’t argue that there’s some connection between certain horror films and these crimes.