Any peace officer who has reasonable cause to believe that the person to be arrested has committed a public offense may use reasonable force to effect the arrest, to prevent escape or to overcome resistance.
A peace officer who makes or attempts to make an arrest need not retreat or desist from his efforts by reason of the resistance or threatened resistance of the person being arrested; nor shall such officer be deemed an aggressor or lose his right to self-defense by the use of reasonable force to effect the arrest or to prevent escape or to overcome resistance. (PC 835a)