Robin is a Killer in His Titans Origin Story
The version of Dick Grayson finally getting "justice" for his family, as told in the Titans universe, unfortunately does involve Tony Zucco being gunned down on a Gotham street. And even if Dick Grayson wasn't the one who put the bullets into Zucco's body, viewers will have a hard time claiming that he wasn't responsible for the gangster's death (and even Dick takes the responsibility). Especially when you consider how angry fans got when Zack Snyder's Batman used excessive force when it could be justified. In Robin's case, we doubt a court would let him off without a punishment.
For those who haven't yet seen the Titans episode in which the case of the Graysons' murder is solved - permanently - much of the story plays out in parallel to the version kept to in the comics. That's the version of the story in which Robin finds Zucco, is tempted to avenge his family, but relents, instead finding closure in taking Zucco down as opposed to ending his life. The Titans flashback distinguishes the main difference: in this version, Tony Zucco was brought down for the Graysons' murder and countless other crimes... but the Feds cared more about his testimony against the Maroni family than Dick's family. So to make sure Zucco doesn't get away with his crime, but is forced to truly pay for ruining Dick's life. Which is where Robin steps in to do the job himself, sidelining Zucco's prison transfer to give him a brutal beating.
Robin Lets Tony Zucco Be Murdered
Some could argue that Robin was definitively planning on killing Zucco, based solely on the fact that he let's the gangster know his civilian identity (a secret he couldn't exactly let slide). But when the time comes for Dick to actually exact revenge and either kill Zucco or let him leave, his good side wins out. Until a carload of Maroni gunmen arrive to kill murder Zucco before he can testify against them and their crime bosses. And as Zucco begs for Dick to help him from being gunned down now that he has incapacitated the police escort... Dick turns away to allow exactly that.
Tony Zucco is murdered as Dick remains silent nearby, getting the outcome that his more vengeful instincts craved, but which his own morals prevented him from taking firsthand. For many fans of the Batman comics, and Robin's own moral code as compared to his mentor's, Dick's decision to abandon Zucco to his murder is an even worse outcome. Emotion driving Dick to avenge his parents? That could be understood. But the makers of Titans wanted to show their Robin standing by and watching as a man he hated was slaughtered.
We'll have to wait and see how this new origin contributes to Dick Grayson's larger story, but for now, Batman fans will have plenty to debate.
Titans releases new episodes every Friday exclusively on DC Universe.