Credit: ABC Family

"Who killed Alison DiLaurentis [Sasha Pieterse]?" is second only to "Who is really in charge of the 'A' team?" on our list of top Pretty Little Liars questions. When we finally learn the answer, will it be completely unexpected — a la Toby (Keegan Allen) being on the "A" team — or is it something fans might predict? In a recent, spoiler-y tweet, showrunner Marlene King shared her thoughts on that very question.

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A fan asked Marlene if Ali's killer will turn out to be a shocker, or something viewers will feel like they should have seen coming. She was nice enough to answer in a fairly direct way, saying, "That's a relative question. In hindsight you might say u should have known."

Okay, so it sounds like Ali's killer won't be someone who has no known connection to the summer she disappeared. Which basically only rules out ... um, Caleb (Tyler Blackburn), maybe? Seriously, Ali had a lot of enemies.
 
Of course, it's also possible we'll find out Ali didn't have a killer at all, because she's not dead. If that twist turns out to be true, it would definitely fall under the category of something that makes sense in hindsight (since plenty of people are speculating about it already).
 
Who do you think killed Ali? Share your theories in the comments below!

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Catch the next episode of Pretty Little Liars on Tuesday, March 12, 2013 at 8 p.m. ET/PT on ABC Family.

Source: @imarleneking

Rebecca Martin is an editor at Wetpaint Entertainment. Follow her on Twitter @BeccaDMartin.