Crime Scene -

If you'll look at the coroners report there was a key ring with seven (7) keys on it found in his pants pocket. There's your answer for the missing car keys.

I agree that the wife did it. She had stated that she was afraid he would turn out like her dad and that she couldn't live like that again. I think he got more and more verbally abusive when he drank so she put the rubbing alcohol in his flask knowing he would fill it up before he went to the meeting. She enlisted the help of her friend Julie to stage the crime scene to look like someone else did it. Chester may be nuts but he kept telling them he knew the victim was dead so that meant he had to have seen something. Then his last interview said he saw a woman in the bushes and that a man was following him. I think Jamie was coming back to watch the fun and was probably still hiding and watching when the police showed up.