I agree they’re pretty evil, if not sociopathic. But 2 things: Erik was remorseful, and even confessed to his therapist because his conscience was eating away at him. I don’t know about Lyle.
As for Kitty and Jose…Jose was pretty evil himself. Multiple friends and family members said they had seen the bruises and/or Kitty had told them Jose beat her. And 2 people testified under oath that the brothers, when they were little, told them of the sexual abuse at his hands. At least one of them testified that they told Kitty, and she did nothing. Her sons were being raped and she did nothing to protect them. Of course she may have been in fear of her life, and that kept her from doing what she needed to do.
I know “that doesn’t mean they deserved to be murdered.” Maybe. And maybe like so many others, Jose’s cruelty created two monsters that he could no longer control through violence.
Anyway the brothers will spend the rest of their lives in prison, so I do think they got justice in the end.