Spoiler...
Dude is guilty. They found his sweat on the hood latch of her Rav 4. The whole vial of blood thing becomes a moot point, they didn't have a vial of his sweat. He (they) had to have killed her somewhere else. He also talked about wanting to make a torture chamber when he got out to someone while he was in prison, and said the best way to get rid of a body is to burn it. He also had soaked a cat in oil or gas and burned it alive. All of that makes him look a lot more guilty than the show suggests.
Dude is guilty. They found his sweat on the hood latch of her Rav 4. The whole vial of blood thing becomes a moot point, they didn't have a vial of his sweat. He (they) had to have killed her somewhere else. He also talked about wanting to make a torture chamber when he got out to someone while he was in prison, and said the best way to get rid of a body is to burn it. He also had soaked a cat in oil or gas and burned it alive. All of that makes him look a lot more guilty than the show suggests.