What is the proper punishment for this attack?

In late May when the riots were just beginning, a man in Dallas wielding a machete was trying to defend a bar from rioters and the rioters immediately started throwing concrete at him, hitting him several times and he panicked and rushed at a rioter in an attempt to scare them away but was then mobbed by I'd say at least 38 people and beaten senseless then robbed. The rioters then laughed and left him to die on the streets when he was completely unresponsive and his hand was broken in so many ways that it didn't even look human anymore and his head was split wide open and he layed on his face in a pool of his own blood. He's last been reported in stable condition but as far as I know, nobody has been arrested or charged and police haven't even looked into this yet. It disgusts me how little is being done after all this time and what's even more disgusting to me is that even in this case, liberals are trying to defend those rioters for attempting to commit first degree felony murder and robbery as well as rioting and many have even made jokes in which they celebrate this. If we had it my way, everyone who touched him would be executed by firing squad immediately, but we all know that won't happen and I'm not optimistic that the police will do anything on this case. What do you believe should be done? by the way the video doesn't get any easier to watch at all, there's your warning.
What is the proper punishment for this attack?
What is the proper punishment for this attack?
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