In Alan Moore's 1988 graphic novel The Killing Joke, the incorruptible Gotham City police commissioner James W. Gordon refuses to kill the Joker after the Joker has, among other atrocities, shot and paralyzed his daughter Barbara. In Gotham, the Fox TV show, it's not clear to actor Ben McKenzie that the young Detective Jim Gordon would make the same choices.
Although McKenzie says in the pilot that Gordon makes a "morally correct decision" not to kill of Oswald Cobblepot, Gordon soon realizes that "the ramifications of making the correct decision is he's created a supervillain. He learns from experience that in Gotham the morally correct decision is not the decision that yields the best results.
"It's a lot of what his evolution in the first season is about." What's more, McKenzie warns, "That moral slippery slope that he's sliding down will only steepen and only accelerate."
But that's part of why we—and McKenzie—enjoy Batman so much. "A 10-year-old boy or girl can appreciate Batman for certain elements, and an adult can appreciate the same story for completely different aspects." And lot of what we already love about Gotham is watching black and white melt into shades of gray. And this is before Batman puts on his cowl.
As for Bat-not-quite-man, McKenzie says, Jim sees in the young Bruce Wayne a lot of himself and recognizes the pain of losing a father at a young age. But as the son of a wealthy, prominent family, which McKenzie likens to "a medieval power structure," this makes Bruce akin to "a boy prince." Their relationship to Jim is clear: "Bruce has to rise to the occasion and step onto the throne and take control, and so Jim is trying to save him from effectively sliding down the same moral slope that Jim is."
His relationship with his fiancée is much more complicated. At first blush, they seem to be a successful couple. "But they're hiding things from each other. He can't tell her what he's had to do on the job … and she's also hiding things from him."
As we know from the last episode, he plans to keep hiding the truth about his work from her. During a discussion about police corruption, McKenzie says, "He's looking at her and asking her, 'Do you think I'm capable of that?' Truth is, he's probably is capable of it at some point down the line."