my first thought too.  second thought was -  i wonder if this guy, being controlling according to his wife,  would have harmed his family had they not left when they did.  he sure was  a mess once it hit the fan.  all the extra over kill next to him by the tub - man, his brain  must have been really twisting. 
  i really hope the girl and his family get the best counseling available - this is devastatingly sad.