I think Uhon maybe warned someone about something that Pierre was planning that night. I think Pierre confided the plan in him. Whatever the plan was, it went bad due to the warning. Pierre retaliated. I'm not sure exactly how the girls fit in.
I know this was months ago, but there is so much speculation that doesn't fit the facts, in so many of the posts here, that it blows my mind. No disrespect intended, but it makes no sense whatsoever that Pierre would have stolen the car of the man that he murdered, thus implicating himself clearly in the murder (of Uhon), unless the entire purpose of his going to see Uhon (who was a friend of his) in the first place was to borrow his car, so he could get out of town as soon as possible.
My feeling is he went there, frantic, thinking Uhon was a friend who might help him, and when Uhon wanted no part in helping him flee from the murder of the girls, or to be an accessory by doing so, and was appalled by what Pierre had done (and called him on it), Pierre lost it (and he was already probably unhinged over having murdered two women-or rather, unhinged BEFORE he murdered them), so he killed him, grabbed the keys, and then drove over to his girlfriend's house hoping she'd come with him. When she was unwilling to go, which was a wise decision on her part, he fled without her, and was several counties away when they caught him, because the WHOLE purpose of his going to see Uhon (who had no part in the drug deal or the murder of the girls and was getting his life together), was to obtain a getaway car from a friend that he trusted, and hoped might help him out.
Pierre has been described as "brilliant" and an exceptional student, not stupid at all, and no one that intelligent is going to steal the car of the man he just murdered (so he can be pulled over in a stolen car and arrested for murder), unless the entire reason he killed him in the first place was to get out of town, and probably out of North Carolina entirely. That makes a lot more sense to me, anyway. If he never stole Uhon's car, he never would have been arrested for Uhon's murder, but he wasn't fleeing primarily because of Uhon's murder, he needed the car to get out of town (or he thought he did) because he'd just murdered two women, by shooting them in the head execution style from the back seat of Alex's car, after ordering them to drive down to the river and robbing them. He probably could have just hid out in Asheville for a few days until the search was over, if he'd had a safe place to stay-if not for the fact that he'd been seen leaving Canterbury Apts with the women, their housemate knew that they'd gone with him, and there were texts between him and Alexandra about the drug deal. Because of that, he knew he would be implicated in their murders (because he murdered them), so he needed to get out of town immediately-hence the murder of Uhon, and the theft of his car.
He might even have asked Uhon to drive him somewhere, or drive him out of NC, but Uhon not wanting to be implicated in a murder by fleeing with him, and trying to live right wanted no part in it, so feeling desperate (and having just confessed to a murder), Pierre not only needed to kill a potential witness against him, but saw an opportunity to get the car he needed at the same time, so one more murder on top of the other two was no big deal at that point... he was in too deep already. That's my opinion and my story, and until there's good evidence to prove otherwise, I'm sticking to it. :O)