It looks like possible and potential spoilers for Arrow season 3 have been revealed as two characters in the show are theorized as Sarah Lance's killer.

Users over at Reddit and 4Chan have been theorizing on answering the question "Who killed Sara Lance?" and it seems that the answer was revealed when alleged leaked information was spread on 4Chan.

An anonymous user claiming to be one of the production assistants of the show has confirmed that Oliver's sister and Malcolm Merlyns daughter, Thea Queen is one of Sara Lance's killers at the first episode of Arrow season 3.

The user claimed that they are shooting the scenes right now where Oliver Queen finds out that Thea killed Sara.

Another theory is that Nyssa's father and Leader of the League of Assassins, Ra's Al Ghul is also suspected to be Sarah's killer by another unknown user in the Arrow Reddit forums.

It remains to be seen whether these two are the Sarah's killers, but judging from what Malcolm said about Ra's during episode 4 of season 3, and the fact he doesn't approve of his daughter's relationship with her, it seems that he's the obvious suspect. But we can't rule out Thea as well, after all she was trained by Malcolm and judging by her training as well as the situation her father is in with the League, it could be a good reason why she killed Sarah in the first place.

Meanwhile, a iconic Batman character is rumored to appear in the show as "The Vampire Diaries" star Steven McQueen will play Dick Grayson, the former Robin and the current Nightwing.

During a fan Q&A on Facebook, comics and webseries writer/actor Kevin Conn asked Stephen Amell what other DC characters he'd like to see on Arrow in the future and other Arrow Season 3 spoilers. Stephen Amell answered with:

"Nightwing would be pretty badass."

Was this a hint at things to come?

Actor Steven McQueen began tweeting about "Nightwing" training and he kept tagging the Arrow writers with his tweets on Twitter. Check out his tweets below:

It should be noted that the producers of Arrow has stated that Nightwing won't appear on Arrow, it could be that they were referring to the fact that Nightwing won't appear on the Arrow season 2 (the rumors of a Nightwing appearance sprang up during the season 2 of Arrow) but on Season 3?

Ra's Al Ghul has already been revealed and an indication that Wayne Enterprises will merge with Queen Industries in the future in the pliot episode of the Flash. It's only a matter of time before we could see one of the members of the Batman family to make there presence known in the show or probably in the Flash TV series.

What do you think of the possible updates and spoilers for Arrow season 3? Sound off in the comments section below.