Dante Trippi is Gregory Valentine's nemesis. When Trippi had caught Valentine poaching on his turf, Trippi fought with Valentine to try and teach him a lesson to never be in his district again, but Valentine fought back which ended in them both having to need medical assistance. While the S.C.U are working on a case, Moto interrupts Backstrom in the interrogation room and informs him just when he happens to be under the influence of drugs that one of Moto's buddies on patrol had told him that Valentine got beat up pretty bad.
Backstrom and Moto make their way to the scene and Backstrom finds Valentine crying out of 'shock' (and not because he's a wimp) in the back of police vehicle and Valentine explains why he got beat up, he was caught poaching on Trippi's turf and they got into a serious conflict. Backstrom leaves Valentine and finds Trippi in the back of an Ambulance handcuffed and laying down on a stretcher.
Backstrom flashes his badge to a paramedic and asks for them to be left alone, Moto closes one of the vehicle doors behind him and leaves one open so that Moto can keep an eye. Backstrom threatens to kill Trippi if he ever comes near Valentine again, grabbing his badge and forcing it into Trippi's mouth. Trippi agrees to never come near Valentine again and Backstrom nods, leaving the ambulance and a jaw-broken Dante Trippi.