The killer had a mask, so facial recognition is impossible. But he has a prosthetic arm, military type, unfortunately we don't see the serial number.

But what is certain. This is because he is a former soldier and given the scars and the third degree burnt left arm, a veteran and given his brutal combat technique, a metahuman.

So we have a veteran, probably retired and returned to the neighborhood where he was born, who is looking to get rid of the gangs. It should be easier than this Chameleon thing.