I would have voted guilty if I was a juror. Did he kill his 2nd wife, no, but all you have to argue is that in the heat of the moment he got messy. Besides the defense didn't give the jurors any other possibility of someone else who could have done it; therefore, I would assume that it was him. If anything, hopefully his daughter kills him next and then she goes away for her crime.
So during the night of the murder, we learn that Wes lied about the coin toss and somehow coerced his classmates to helping him kill Sam. But that's pure speculation on my part if all along he planned on killing him. We also find out that Wes and Rebecca are together. Well that I did see coming, but what I didn't was how is she involved in this? How does the group even know her and why would they help?
If I had to guess I think Annalise is right in speculating her husband was involved with the dead the girl. I mean why else would he delete all his emails to and from her. My theory is Rebecca is also a student of his and once Sam killed the dead girl because she was going to tell Annalise about their affair, he moved on to Rebecca and when she wanted to end it because she fell for Wes, Sam tried to kill her, but Wes and the team found out about his plan and decided to get to him first. That's my theory as of now, but it's subject to change.