First Idea

A college student (Tom) rings his friend (Dick) up explaining that his car has broken down and he needs a lift. Dick comes to help and finds out that Tom had stabbed and killed a gang member and he needed help to hide the body. Dick is terrified as the gang member was part of a dangerous group. They then quarrel in the car park.  Tom sits in the car and tells him to get in. Dick sees his girlfriend with her friends and tells Tom he'll be back in a minute. Dick goes to his girlfriend to seek advice but she first goes to the toilet. One of the girls say that she had been cheating on him with Tom.

Dick's anger overwhelms him. He goes to the car and doesn't mention anything. He drives to a forest to bury the body where he confronts his friend. As they are burying the body they start to fight and Dick hits Tom in the head and Tom instantly dies. Even though he did not mean to kill him, he is now dead and panics. He then plants the shovel in the gang member's hand and the knife in Tom's hand.