If I were in Sam's shoes I would follow his father, non-violence is superior because violence will only cause more conflict and non-violence will be more effective in the long run. Protesters practising non-violence are innocent and if the police or other assailants harm them they are victims, giving them more credit in the public's view. Organizations practising violent protest can be villianized no matter how righteous their cause. (Sticking a gun in someone's face because they are a butt-head, no matter how satisfying will not change them, they will still be a butt-head.) However, in a situation like Stick's it would be easy to understand why the black panthers are so alluring.