Two of the earliest names associated with the DC Universe to ever appear on the fan-favorite FOX series Gotham vanished during the series' first season, and months after its competion, fans are still wondering whatever happened to Renee Montoya (Victoria Cartagena) and Crispus Allen (Andrew Stewart Joes). In a Reddit thread that picked up quite a bit of steam last month, one fan asked others what they thought happened to the characters who, in the comics, would go on to become the superheroes known as The Question and The Spectre. While neither of those characters has popped up in live action yet, both have been rumored off and on in various projects over the years.
The closest either got was when Emmett Scanlan (Krypton's Lobo) appeared on Constantine as James Corrigan. His first appearance in the role aired just a couple of months after the Gotham pilot, but while Corrigan's story was all about the Gotham PD, Corrigan (who was also a cop on Constantine, though not from Gotham City) was spied in a vision by Zed (Angelica Celaya) as a disfigured wraith surrounded by a halo of green, an obvious reference to Corrigan's destiny as The Spectre. That series was cancelled after one season and Corrigan never even died, let alone revived as The Spectre. Allen also appeared (although unnamed) in Justice League.
It's Renee Montoya who will appear on the big screen first, played by Rosie Perez in Birds of Prey (And the Fantabulous Emancipation of One Harley Quinn). She will likely not morph into the faceless Question in the film, although there is no solid information one way or the other at this point. Montoya, created for Batman: The Animated Series, was created to be a cop in Gotham and eventually evolved into The Question when the original (Vic Sage) died. Allen, on the other hand, was seemingly created with his destiny as The Spectre in mind. He was killed by a descendant of Corrigan's, who by that point had long abandoned the spirit of The Spectre and gone on to his own eternal reward. After a period of time where The Spectre was Hal Jordan, Allen's murder gave The Spectre a noble host to glom onto.
It's also worth mentioning that Harvey Dent/Two-Face (Nicholas D'Agosto) vanished, too (after FOX had done a great job of promoting the character, familiar as he was to casual fans from Batman Forever and The Dark Knight).
You can get Gotham on Blu-ray and DVD now. the series also streams on Netflix and Hulu.