Of course, if someone in their association did have those skills, he would become a person of interest quickly.
Has the timeline of the activities of the dating couple been completed? There was like a four or five hour gap after they left the fraternity party until they were accounted for at the house. I have a hunch that something important to the investigation happened to them during that time and the police are withholding that information so as to not compromise the investigation. Might also be why the police could so confidently state that the attacks were targeted because of what they know happened in that time frame to that couple. The whole food-truck, multiple phone calls, and who gave them a ride home stuff might have been totally unrelated to the crime and these two were collateral damage in the attack that was directed at the dating couple.
My guess is the two cute girls were the target and the couple was collateral damage. But, again, that’s just a guess.
Guess we’ll find out in due time. I suppose.