Pacman Jones not only cheated at the blackjack table before his February arrest ... he also smacked the hell out of an officer's arm -- and it's all on video obtained by TMZ Sports.
As we previously reported ... the ex-NFL star was busted three months ago after he was caught "capping bets" at an Indiana casino.
You can see the video ... Jones places a bet -- and when he realizes he's won the hand -- he sneakily adds another chip.
The problem?