If police have no person of interest in the case and the baby turns out to be Collins', then by default he would be the primary suspect, no matter what police initially say. That's just how it statistically works. But I would say in his favor, knowing nothing about him personally, killing your pregnant girlfriend days before the NFL draft, even if you think you committed the perfect crime, would not be fiscally advantageous (and that would be the perceived reason why you'd be committing the murder), because the spouse/significant other is usually the primary suspect...
I would NOT select him at #63. If he's there with their 5th rounders, maybe. It is a organizational black eye no matter where he is drafted, as he would be associated with your team in news reports about a murder, if he ends up being charged in the case, so there are draft capital and reputation risks for Pete, John and Paul.