"Convict and a robber" seems like the appropriate description to me. They could also be convicted of any number of things, that aren't robbery. By saying conv

"Convict and a robber" seems like the appropriate description to me. They could also be convicted of any number of things, that aren't robbery. By saying convicted robber, you're assigning more certainty to your claim that they're a robber than there is. You're trying to argue that they're a robber when you're saying somebody is a robber and they haven't been convicted of robbery. Saying that they're a convicted robber pretends that it's already been proven beyond reasonable doubt, which it hasn't