Movies that are mostly about psychology, not needing to be gore-based. I feel that the serial killer movies tend to be lame, but maybe that has a lot to do with real serial killers being rarely of any high intelligence OR being primarily sexual deviants. I am looking for loner-killer movies :)
Maybe some incel killer movie, if there is one (?) (not the Joker :D ) Though it'd appear that real incel killers also were on the dumb side of things.