It is a good time to ask ourselves what we would do in the lawmens place. If it were our job to arrest the perps and we had been warned he bragged about dying rather than being in a cell. Then he separated himself from the other perps with his hands in the air, then he lowered his hands and reached for his waist. Would it depend on how fast of a shot you feel like you are, would you wait until you saw the flash from his gun or what?
Wait and shoot the gun out of his hand like Wyatt Earp or just kill him like Marshall Dillion.