Viviano is a guard that worked in the Green Dolphin Street Prison three years, after working in a Miami customs house prior. Vivano takes pleasure in antagonizing convicts, and even makes bets with fellow guards when doing so. He's mentioned that he believes prisoners are the scum of society. Being a guard, his job involves detaining prisoners everyday, and by doing so has mastered certain techniques that prevent them from struggling, such as effective headlocks.
(Source: JJBA wikia)