Many people seem to be ridiculing this theory, but I think it's worth talking about or at least considering. IMO, it's no more absurd than some of the other motives proposed here like retaliation or revenge.
I personally believe that this was most likely a sexually motivated crime. However, there are some things about that theory that don't sit right with me. For example, many predators who attack adolescents do so not out of particular preference but because of accessibility and ease of control. How does that fit with the decision to assault a pair of girls? Two girls means twice as many variables.
Hatred, for either of the girls individually or for something they may have represented to his twisted psyche, could explain some of his behavior. And hatred as a motive doesn't have to be inconsistent with sexual motivation -- think of Gary Ridgway, who believed that he was on a moral crusade to rid the world of unclean prostitutes -- which didn't stop him from having sex with them.
I don't think it should be rejected out of hand just because the girls weren't his chronological peers. If his emotional self was stunted during adolescence, it could be the behavior or appearance of adolescent girls that triggers some sort of pathological rage inside of him.
All my opinion only.
nothing rude intended jmo
