Troian Bellisario Troian Bellisario

Could Pretty Little Liars' Spencer be "A"?

"That's my favorite thing to wonder, actually," Troian Bellisario tells

As the girls have been working toward figuring out who killed their friend Alison, they've found one of their own has come under suspicion. All season long, the mysterious "A" has been one step ahead, and has gone even further in recent episodes to pin Spencer as a possible murderer. Bellisario says she hopes her character has a bit of a shady history.

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The actress also says that looking guilty has led to a new understanding for the other Rosewood resident, Toby, who has been through the same thing.

"He's the only person that comforted her and totally accepted her. That was really beautiful," she says, adding: "It was the only relationship that takes an entire season to unfold."

Watch the interview below (and find out her real thoughts on Toby's stepsister, Jenna).

Pretty Little Liars airs Mondays at 8/7c on ABC Family.