Following the night Marvin Acme is murdered, Santino visits Eddie at his office and scolds him for taking R.K. Maroon’s job of invading Acme’s privacy to take pictures of him playing patty cake with Jessica Rabbit stating he would’ve given him money if he needed it so bad before he tells him of what happened and how Roger Rabbit is the prime suspect. Later, they both visit the crime scene at the Acme warehouse, where they meet with Judge Doom. Santino informs Eddie of Doom's background when he bought the election to become the presiding jurist of Toontown. They both also witness a demonstration of the Dip's effect on a Toon, as Doom maliciously melts an innocent Toon shoe.
Santino isn't seen until after the climax of the film. At the warehouse, he and the police learn it was really Doom, who not only murdered Acme but R.K. Maroon and Teddy Valiant as well. He's then given the rope to the safe that was dropped on Acme as Eddie speculates that the dried paint found on it matches that of Roger's glove. With all of this, Roger is cleared of the murder charge and his innocence is proven.
Hardly anything is known of his history with Eddie, but it can be presumed they've probably known each other during their respective tenures in the police force, prior to the events of the film. Though he carries a stiff demeanor, he looks out for Eddie as he's concerned about his alcoholism and disapproves of his improper conduct toward any superiors.
Santino is a character created for the film, and does not appear in the original novel Who Censored Roger Rabbit?
Richard LeParmentier also played Admiral Motti in Star Wars. He was the imperial officer who gets force choked by Darth Vader after bluntly disrespecting his faith in the force.
Comics:Sunshine • Nightwing • C.B. Maroon • Rick Flint Deleted:Captain Cleaver • Voltaire Other:Lenny the Cab • List of cameos in Who Framed Roger Rabbit