The video shows a cop that needs to be charged and convicted for homicide. The guy with a broken tail light is running away and has no weapon, he is not at that time a danger to the officer or anyone else.
Note as soon as the cop handcuffs the guy he immediately returns to pick up his taser and then drops it by the body of guy he shot. Why would he do that other than to make it look like there was a struggle between the two of them where the body lay? But there is video and he is caught. Lock this cop up he is a violent criminal.