I’m not sure either. But I would definitely ask an attorney. No harm in asking.
The problem is that in order to have a cause of action for libel/slander you have to prove harm.
The only person really being directly harmed by the lie is the officer who shot him with full justification.
I would still ask an attorney. Asking is harmless.
Except it will generally cost you 50.00-200.00.
I would still do it if I were being accused of murder by a popular web site. Maybe do a go fund me? He would probably raise 10,000 bucks in 20 minutes. 
I"m lost. Other than the cop who killed him who is being accused of murdering him?
Anyone else who is specifically accused of his murder and can show to have been harmed as a result would have a cause of action but doubtful anyone else could even get past the CH door and might be severely sanctioned for filing a frivolous lawsuit if they diid.
Nobody else. Just officer Wilson. 
He is the one being slandered.
Unfortunately as a public official I don’t think he can sue since he was a cop at the time.
