Nope, not needed. It's designed to be online (even when playing SP). Plus, it's an indie game and it's easy to rank up and unlock stuff (at least on the first two levels, the others....are a pain)
EDIT: I forgot to add IMO after not needed. Also the AI for the cops is pretty impressive, if a bit dumb at times. It's worth the cash I paid for it (insrt bank heist joke here), but like I said not needed, IIRC, CH don't make trainers for online only games do they?
[Edited by Celticfang, 10/20/2011 3:49:34 PM]
--------------------------------------------------------------------------- Stolen from a close friend in the States:
Here I am...I'm not smart, I'm not pretty. BUT YOU LOVE ME ANYWAY!
Well games that are online that do have trainers off the top of my head: Sanctum, Dead Island, Godfather 2(I know its a stretch), Rainbow Six Vegas 1 & 2 (options for online)
Those are the one's that have the option to go single player but still have a ranking system in them.