Here are the five people we are suspecting the most right now.
Why she might be "A": The show seems to be pointing us in this direction. Mona was convinced she'd found proof Ali is "A" and then — wham, she's dead. Suspicious much? Based on everything Mona was saying and doing this week, Ali would have the most reason to want her dead, and if Ali has been "A" all along, we have no doubts she's capable of doing the deed. Plus, she does seem to be building an army, which is a pretty "A" thing to do.
Why she might not be "A": The Liars have said the words "Ali is 'A'" outloud. On this show, that's normally a surefire sign the person in question isn't "A.”
Alison DiLaurentis's Twin
Why she might be "A": The twin theory lives! Now that we have proof that Bethany had a strong, complicated connection to the DiLaurentis clan, we can't help but think someone from that fam is behind her murder, and could be "A.” Does also have a psycho twin who is behind this all? It's possible...
Why she might not be "A": Well, we still have nothing resembling proof she exists. If she doesn't exist, she can't be "A".
Why he might be "A": Bethany may have been killed because of her connection to the DiLaurentis family, but that doesn't mean Ali was directly involved. Could Jason DiLaurentis (Drew Van Acker) have been "A" all along? Would he be willing to kill his own sister to keep his family's secrets? He's often MIA at key times, and he could be doing "A" work.
Why he might not be "A": Although Jason has had his darker moments, his love for his sis seems real, and we have a hard time buying him as the mastermind behind torturing the girls. Mostly, we don't want Jason to be "A". Despite his bad moments, he's one of the better guys on this show.
Why he might be "A": We know Mrs. D was having an affair with Bethany's dad. We also know Mrs. D was having an affair with Mr. Hastings (Nolan North). Could Mr. H be Bethany's dad? Could Bethany be a dark Hastings family secret? (Perhaps one Spencer doesn't even know about.) If someone in the DiLaurentis killed Bethany, would Mr. Hastings snap and go "A" as revenge? We could certainly see him killing to keep his secrets...
Why he might not be "A": Why would he go after his own daughter? For that matter, why would he go after any of the Liars other than Ali? Also, as a grown man, wouldn't he have better ways of dealing with his anger and secrets than becoming a crazy stalker?
Why he might be "A": Wren Kingston (Julian Morris) is clearly involved with all of this somehow, and some of his closest ties are to Radley. He knows the institution's secrets — maybe he'd kill to keep them.
Why he might not be "A": He's been MIA for a long time now. On one hand, that means he could be busy doing "A" things, but on the other, if he really was "A," wouldn't the writers want to keep him a little more on our radars? And we're still not sure exactly what his motivation would be for going after the other Liars.
Who do you think "A" is? Let us know in the comments below!