Wolves at the Door (2016) is a slasher film inspired by the Manson murders of 1969. But this particular film is just a plain slasher film with no real story in it. The slashers, a man and three women presumably Charles Manson and his groupies, their faces are never seen. You only see them in shadows. No depth into any of the characters.
On the plus side of things, it does have plenty of jump scares if that's all you are into. But this film has no insight into the real life murders of Sharon Tate, Jay Sebring, Abigail Folger, or Wojciech Frykowski. The film is just a dumb slasher flick, nothing more.