David will get off the hook for murder and heres why
1. Tapes were tampered. A moron lawyer could easily show that he did not commit it.
2. David has probably no priors. At worst he probably had a speeding ticket. The court will question his motive for going on a killing spree.
3. The bank account records show he withdrew all his money. He could convince the court that he was trying to payoff the killer.
4. Why would his friends just sit around while he tries to drown them.
5. He was inside when the car crashed into the ATM.
6. His keys do not lock the car, he could prove that someone jacked it and was using it.
7. David is a banker, which requires a decent amount of intelligence. He could explain he was kicking the machine in the video in order to call security.
and much much more. He would be deemed innocent by a lack of sufficient evidence.