Henchman of retired gangster Sam Vittorio.
Jojo and Monk carry out Vittorio's orders, assisting with the jail breakout of Vittorio's former partners Connie and Floyd (actually Max and 99 to whom they bear a remarkable resemblance), rendezvousing with them at Danny's Diner and finally delivering them to Vittorio's residence.
To do this they disguise themselves as cops - albeit with mistakenly stolen firemans' uniforms. The victims of this theft were later found walking on Route 63 in their underwear.
Note that although the name Jojo appears in the credits, it is not used in the episode itself.