Couple of things
Kicking and stamping on the guys head is not the officers job, he lost his temper and i dont want an officer with a gun losing his temper . He attacked the other guy who had his hands on his head and was equally going nowhere as well
The officer had a tasar in one hand and a gun in the other , the guy on the floor was going nowhere
The police just cant lose it like that , he could have killed the guy on the floor , kicking and stamping on the head can cause death or brain injury
He needs to lose his job