Our Final 6 Suspects For "A.D." on Pretty Little Liars

The Best Explanation: To this day, it's possible that Lucas has never been able to recover from the girls' intense bullying. The years of torture and emotional abuse are enough to drive anyone wild. Lucas's hatred for Ali has always been palpable. In fact, he's been a frequent "A" suspect throughout the entire series because of this obvious disdain. At one point, he's clearly on the "A" team but isn't running the show. Maybe he decides to take the game into his own hands once Charlotte gets murdered. And let's not forget that Lucas grew up with Charles (who, as we know, becomes Charlotte). Finally, he sees the opportunity to make everyone pay for what they've done to him . . . and for the death of his childhood friend.

The Most Damning Evidence: Lucas's connection to Charles aka Charlotte is likely the best and most concrete evidence we've got. Circumstantially, though, there's a lot more to consider. Lucas has an apartment in Rosewood, which he could very well be using as a lair. He's also rich and a tech genius. It's clear Lucas has the money to pay for (and program) the kind of technology "A.D." needs to terrorize the girls. Lucas has always been shady, so why should we trust him now?