An ex-federal prosecutor is weighing in on Diddy's assault video -- and she says while this isn't necessarily a smoking gun in the investigation he's facing, it certainly doesn't help him.
We talked to Katie Cherkasky -- who's had years of experience with these sorts of legal matters -- on "TMZ Live" Friday ... where she declared that the now-viral video, in which Diddy can be seen beating Cassie -- should make him and his camp worried.
