I hate hoodlums and gang bangers, probably more than most folks. I think that they live by the sword, and deserve most of what they get. This goes way overboard.
The suspect was down, submissive, and surrendering. Whatever he's done up to this point, he's now adopted a non-threatening posture. Cuff and secure him, haul him in, handle him according to the law. Baton shots are possibly justifiable in a severely combative suspect, but I cannot imagine any agency having a standard procedure which authorizes penalty kicks using a subject's head.
On a lighter note, he'd have been fine if he'd obeyed some simple guidelines. (Not embedded because it's somewhat NSFW.)