AD Theory
So I've Rewatched The First Episode Because We All Know That AD Is A Character In The First Episode... The Girls Started Their First Secrets One Year Later After Alison's Disappearance, The First Secret We Saw Was Aria And Ezra Who Turned Out To Be Her Highschool Teacher, The Second Secret Was With Hanna And Mona Which Was Shoplifting It Is Also Revealed That Mona Was The First A, The Third Secret Was Emily And Maya Who Were Into Each But Maya Is Murdered In Season 2 Which May Or May Not Come Up In The 7th Season And Finally The Fourth Secret Was Spencer And Wren Who Shared A Kiss Which Melissa Later Catches Them But The Major Secret Was The Jenna Thing!!!
First Theorie: I Think -AD Is A Character Who Isn't In Those Secrets Who Are Alison, Ella, Mike, Byron, Ashley, Pam, Melissa (Sort Of), Jenna (Sort Of), Meredith and Darren Wilden.
Second Theorie: I Don't Think Any Of The Parents Who Are Ella, Byron, Ashley And Pam Would Want To Hurt All Of The Four Girls Or Even Care For Charlotte.
Third Theorie: The Characters Left Are Alison, Mike, Melissa, Jenna, Meredith And Darren, And Characters Who Didn't Appear In This Episode Or Were Played By Different Actors Are... Caleb, Toby, Veronica, Paige, Mary/Jessica, Jason, Lucas, Peter, Noel, Garrett, Linda, Sara, Cece/Charlotte And Ian. Darren, Jessica, Noel, Garrett, Sara, CeCe/Charlotte And Ian Are All Dead So They Cant Be AD.
Fourth Theorie: Jenna Isn't AD But Was Blackmailed Into Trying To Kill The Liars Including Alison, Meredith Doesn't Have A Motive To Hurt The Girls Or Care For Cece But Jenna And Cece Were Freinds She Even Said It Herself, Meredith Is Also On A New Show So She Won't Be Coming Neither Will Mike He Is Also On A New Show.
Fifth Theorie: This Leaves Us With Only Alison And Melissa Who Probably Don't Like Each Other But Also Both Have Motives... I Think If Alison Wanted To Hurt The Girls Its Because Spencer Is Cece's Sister And Alison Was Jealous Because Cece And Her Were Close And Cece Lied To Her, Alison Would've Only Wanted To Hurt Spencer But The Girls Were In Her Way So She Decided To Hurt Them As Well.
If Anybody Wants To Know Melissa's Motive Ask And Comment Below???