When news broke last month that Joseph Gordon-Levitt was likely joining Christopher Nolan's 'The Dark Knight Rises,' comic geeks and Internet movie bloggers dashed off to their own personal Batcave to try and figure out just who the actor might play. Speculation was rampant and covered a variety of characters from Batman's infamous rogue's gallery, including the Riddler and Deadshot. Those two bits of speculation didn't pan out, but one other popular choice appears to be correct.

Variety says JGL is set to play Alberto Falcone, better known as the Holiday Killer. If you're scratching your head wondering, Who the hell is Alberto Falcone?, you're probably not a big comic fan. Allow us to get you up to speed.

Alberto is the son of mafia kingpin Carmine Falcone (played by Tom Wilkinson in 'Batman Begins'). Unlike his siblings, Alberto wasn't allowed to become involved in the family's business, so he went to Harvard and Oxford instead. However, the crime gene couldn't stay buried forever, and when some of Gotham's most notorious criminals got murdered in the graphic novel 'The Long Halloween,' it turned out to be Alberto -- dubbed the Holiday Killer -- who was behind the homicides. He eventually wound up in Arkham Asylum and later reappeared in the 'Dark Victory' story arc.

As Variety points out, including a character like the Holiday Killer makes a lot of sense, given Nolan's intentions to keep his Gotham City grounded in reality. While it would have been fascinating to see the filmmaker's take on the Riddler, this role suits Gordon-Levitt nicely. He even bears a bit of a resemblance to Alberto Falcone.

Nolan hasn't given us any indication as to what might happen in the script, which will most likely be his final 'Batman' outing, but we do know that Gordon-Levitt will be joining fellow 'Inception' thespian Tom Hardy (set to play Bane) and Anne Hathaway (Selina Kyle / Catwoman). Batman looks like he could have his hands full this time out. In the hands of a lesser director, we might worry that Nolan was adding too many villains to the mix, but given his track record with the previous 'Batman' films, we're trusting him completely on this one.

Turns out that isn't the only casting buzz surrounding the project, either. Apparently Juno Temple, fresh off her critically acclaimed performance in Elgin James' 'Little Birds,' is also being considered for a part. No details on who the young starlet might play, but the description being tossed around is "a street-smart Gotham girl." Sounds like a smaller supporting role, but Nolan may surprise us.

Warner Bros., as is standard procedure, has refused to respond to the rumors. What do you guys think? Is Alberto Falcone too obscure to get excited about or do you think Nolan can make him appealing to an audience who isn't familiar with the character? Chime in below, and check out 'The Long Halloween' if you want to get familiar with the Holiday Killer prior to 'The Dark Knight Rises' July 20, 2012, release date.