Jenna (Tammin Sursok) has been a prime “A” suspect since the very first episode of Pretty Little Liars. And the evidence against her keeps mounting, especially since we found out in Season 2, Episode 24: “If These Dolls Could Talk” that she lied to everyone (even Toby [Keegan Allen]!) about her blindness. Here’s a breakdown of all the reasons why all “A” signs point to Jenna.

Revenge, Part 1. Like Emily Thorne on Revenge, Jenna has plenty of reasons to torture the Little Liars. Even though they were merely acting as Alison (Sasha Pieterse)’s agents, they contributed by association to Ali’s vilification when Jenna first arrived in Rosewood. Ali tried her best to embarrass Jenna at Noel’s (Brant Daugherty) Halloween party in Season 2, Episode 13:”The First Secret”, and the girls just stood by and allowed it.

Revenge, Part 2. Three words: The Jenna Thing. Adding salt to the wound, Ali decided to scare Toby by setting off fireworks in his house — Ali claimed that she caught Toby spying on them through his window. The unplanned fire wound up blinding Jenna (or did it?), forcing her into a rehabilitation center for blind people, and doing who knows how much emotional damage. Jenna knows Spencer (Troian Bellisario) was closely involved in the incident with Ali, and the Little Liars were all there.

Sleeping With the Enemies. Jenna’s romantic conquests have all been notorious enemies of the Little Liars. Her secret relationship with Garrett (Yani Gellman) has always been spooky, considering how badly he seems to want the Little Liars behind bars. Her more recent partnership with Noel is even creepier, since Noel has been trying to scare and blackmail the Little Liars since Aria turned him down. The scene in Season 2, Episode 19: "The Naked Truth", where he and Jenna are standing in a dark room across from a whiteboard featuring everyone’s secrets (including “I know who killed Alison DiLaurentis”), seemed to solidify their anti-Little Liars bond.

Credit: ABC Family Channel © 2011 Disney ABC Television Group Photo: So Did Jenna and Garrett Kill Ali? Marlene King Explains!

The Tape. In Season 2, Episode 23: “Eye of the Beholder”, we first saw the incriminating tape showing Jenna, Garrett, Ian (Ryan Merriman), and Melissa (Torrey DeVitto) in Alison’s room, all looking for Alison, and trying to make Jason (Drew Van Acker) look guilty in their NAT club spying games. Jenna is clearly in on the rouse, and we already know that any relationship to the secret videotape club is a bad sign. 

Page 5. In Season 2, Episode 12: “Over My Dead Body”, we saw Jenna giddily conspiring with Garrett about the elusive Page 5 of Alison’s autopsy report, the one that reveals how Alison really died (with dirt in her lungs, insinuating she was buried alive). While this served to identify Jenna as a possible murder suspect, her decision to stab Garrett in the back in last week’s episode by claiming she had no idea what it was, and that Garrett had told her to keep it safe, said a lot about her “A” capabilities. 

Brotherly Love. Her creepy attachment to Toby has always defined their step-sister/step-brother relationship, but it was the revelation in Season 1, Episode 10: "Keep Your Friends Close" that she had seduced him into a quasi-incestuous situation revealed just how strongly she loves him. Emily emerged as a friend to Toby, even when he was wearing his ankle bracelet and accused of killing Alison. And, of course, the Spoby relationship has not made Jenna a fan of Spencer’s.

Find out who “A” is on the Pretty Little Liars Season 2 finale on Monday at 8 pm ET/PT on ABC Family.

Pretty Little Liars airs Mondays at 8 p.m. ET/PT on ABC Family.