With each passing week Pretty Little Liars gets closer and closer to the series finale, and as promised these final 10 episodes will answer all the questions fans have been asking over the years. While the biggest question is, of course, who is A.D., there's some other questions the show needs to answer, starting with who killed Jessica DiLaurentis on Pretty Little Liars? Thankfully, this week's episode will finally answer that mystery.
Jessica was killed off during the season finale of Season 4 and the mystery of who killed her has been one that has bothered fans for years. All fans know for sure is Charlotte buried her body in the Hastings' backyard, which was later uncovered by Alison's dog. Based on everything Charlotte revealed when she came clean about being A fans have accepted that she wasn't Jessica's killer, but who else had motive to kill Jessica? Actually, a lot of people did.
The most likely suspect is Mary Drake, her sister. There was clearly no love lost between them. Mary made it clear she hated her sister and resented her for putting Mary into Radley. She hated her sister so much she pretended to be her just so she could sleep with Spencer's dad who she knew was having an affair with Jessica. Maybe when Mary got out of Radley, or snuck out of Radley, she killed Jessica as an act of revenge for all the things Jessica did to her over the years.
There's also always the possibility that Jessica is actually alive and Mary Drake is dead. This theory is based on what happened in the books in which, Alison was the one with a secret twin and the Alison that died was actually her twin sister Courtney. Courtney had switched identities with her sister so that Alison was the one sent back to Radley while Courtney took over Alison's life. In an act of revenge, when the real Alison came home she killed Courtney and let everyone continue to believe that Alison was the one who was missing, keeping the truth a secret for years.
Anyway, this theory is pretty much the same idea. Mary Drake at some point assumed Jessica's identity so Jessica would be the one put in Radley so when the real Jessica got of Radley she took her revenge by killing Mary Drake, who everyone believed was Jessica.
It's confusing and may be a bit of stretch but it's also just believable enough to be true. Thankfully, fans won't have to wait much longer to find out who really killed Mrs. D.