Yes, the evidence for this is the (not discussed or discussible) violent p*rn he was consuming. Presumably, that was the fantasy he was wanting to act out. There doesn't seem to be any evidence he was into slasher movies or mass-murder video games.I think he had maybe seen Maddie through her window during his previous trips, and maybe fixated on her. He had no way of knowing KG was there that night, much less in the same bed.
If everything went according to plan, I think she was supposed to be the only victim. Unfortunately, just minutes before he arrived, Xana had ordered food, which meant she was up and about. That ultimately put two additional victims in the crosshairs.
JMO