None mentioned, but evidence makes a pretty good witness. GSR or gun shot residue, blood splatter, no evidence or history of fights/brawl between the two, did the convenience store clerk note any hostility between the two, and if there were no injuries to the "barber", and all the evidence match the barbers statement, the barber likely walks and appears he did.
Oh yes, and insurance policies...Did the barber have a hefty life insurance policy on the decedent? All of this stuff would cause the cops to dig deeper..Evidence often makes up for lack of witnesses.