It's very bad to kill someone.
Terry is being held up by a young criminal with a knife who is demanding all his belongings.
Terry wants to defend himself.
Terry disarms the young man and calls the police for back up.
Terry defends himself and overpowers the young man which results in his death.
The young man learns from the incident and changes his ways.
The young man's family has to mourn the loss of a family member.