I Know What You Did..To Toby's Mom & Ali -PLL Theory
~features: Wilden, Jessica, Peter Hastings, Ali, Jason, blackmail & more~
Let's think about what we know about Jessica DiLaurentis aside from her creepiness. We know that she saw who threw the rock at Alison in attempt to kill her. Additionally, instead of calling the police like your average mother would do in this situation, that Jessica buried Alison in her backyard. There has to be a good reason that Jessica didn't call the police, and maybe it's because a police officer was already present at the scene of the crime. Perhaps Wilden threw the rock at Alison.
A lot of fans are assuming that since Jessica chose to protect the person who threw the rock at Ali, that the person must be someone related to and/or very close to Jessica. However, we could be dealing with something entirely different, something blackmail related. We know that Detective Wilden loved blackmailing people, including Travis's father and Ashley Marin.
Because of the plot line involving Toby's mother, we learned that Jessica DiLaurentis is on the board at Radley, the same place where Toby's mother died. Jessica DiLaurentis is on the board of a mental institution where somebody made a false report regarding Mrs. Cavanaugh's death. Toby thought that his mother killed herself until "A" gave him clues that actually led to something real about how his mother died. Toby and Spencer discovered that it would have been impossible for Toby's mother to have jumped to her death the way she allegedly did according to the false report. Spencer followed up on this information with Eddie Lamb, and she learned that Wilden played a large role in the creation of the false report. Eddie Lamb strongly implied that Wilden gained his promotion from officer to detective as a result of the false report about Mrs. Cavanaugh's death.
When Spencer and Toby told Spencer's father what they had learned, Peter initially planned to take down Radley completely. Something changed his mind, though. Spencer noticed that Mr. Hastings' behavior was very uncharacteristic of him when he suddenly encouraged Toby to accept a settlement from Radley instead of proceeding in taking the place down. He presented a story to Toby claiming that while Mrs. Cavanaugh's death wasn't a suicide, it wasn't a murder either. Apparently, another patient, a patient described as "fragile," was with Mrs. Cavanaugh when she died, and the false report was made to protect this fragile patient. Getting involved in that sort of protection is a huge risk for anyone. When Spencer started questioning her father about this, he forcefully ordered her not to speak with Jessica DiLaurentis about any of this.
Whoever this fragile patient is, it appears Jessica wants it a secret as well, and that the secret is very important to her and to Peter Hastings. As many people have pointed out, it would make sense that Peter and Jessica would have a shared interest in protecting Jason, since he's their son. This is why many people have guessed that Jason is the person who threw the rock at Ali. We also know that Jason has dealt with mental issues in the past. Is it that outside the realm of possibility that Jason could be this fragile patient? Perhaps he spent some time at Radley himself, and was in some way involved in what happened to Toby's mother. He could have pushed her either intentionally or by accident. Either way, Jessica and Peter are not the type of people who would want that type of information to get out.
Jessica and Peter could have paid Wilden off to create the false report, leading to Wilden getting promoted at work, and inevitably gaining information to use against Peter, Jessica, and Jason. This could all have been part of Wilden's agenda. Alison had a lot of enemies, and there's no reason to dismiss the possibility that Wilden was one of them. He could have wanted to kill Alison. Wilden had gathered enough blackmail information on Peter and Jessica to avoid having them ever turn him in if they suspected him, and, the icing on the cake, made sure that HE would be the head detective on Alison's murder investigation, so if he was involved in what happened to Alison, he'd never get caught.
It's also possible that Alison and/or CeCe was also involved in what happened to Mrs. Cavanaugh. One of them could have either helped Jason or seen what he did. We've been told that Jason and CeCe used to date, so it would make sense that if Jason was a patient at Radley, CeCe would visit him. It would also make sense for Jason's sister, Alison, to visit him there. This could explain Dr. Palmer's attempt to warn Toby's mother to stay away from "that blonde girl." It's also possible that he was referring to Jessica when he said this. Either way, if Jason had something to do with Mrs. Cavanaugh's death and Wilden helped cover this up, that would definitely explain why Jessica buried Alison instead of calling the police and reporting what she had seen. Additionally, Spencer has brought up, numerous times, that she and Jason have a lot in common. One of their newest similarities is that they both have parts of their lives that they don't remember due to being under the influence.
It's possible that Jason was involved in Mrs. Cavanaugh's death and he doesn't even remember it. This could mean that Jessica and Peter are not only counting on Wilden to keep what happened a secret from authorities, but also from Jason. If Wilden threw the rock at Ali, it would be his word over Jessica's. If Jessica didn't keep Wilden's secret, Wilden could have tried to pin the rock being thrown at Ali on Jason, AND he could have revealed Jason's involvement with Toby's mother's death. Lastly (for now), we know that Jessica paid CeCe to keep a secret about something she saw on the night Ali disappeared. Maybe she saw what Wilden did, didn't understand why on earth he should be protected, but was forced into it by Jessica. Jessica could have also had Peter's help with this; we know that he has a lot of money. This wouldn't be the first time we have heard about Peter and Jessica protecting Jason; they also changed Jason's grandmother's will so that people wouldn't think he was involved in what happened to Ali. Maybe they had to do this because they were worried about Wilden framing Jason for that AND exposing what Jason did at Radley.
Also, Ali finds out everybody's secrets; maybe Ali found out how Wilden REALLY got his detective status so quickly and threatened to expose the truth. It would fit in with both of their character traits. Ali could have suspected that Wilden was "A," and maybe that's why she was trying to get all of that money before she disappeared. We have seen someone else try to gather money to get rid of Detective Wilden, Ashley Marin.
Other small clues supporting this idea:
--The PLLs constantly mention/learn that the cops in Rosewood can't be trusted
--Wilden obsessively tried to pin Alison's murder on the girls to the point where it was abnormal. Maybe he was doing this to cover up his OWN involvement.
--We know that the prosecution on Alison's murder case (an investigation with WILDEN as head detective) planned on exhuming Ali's body, but somebody beat them to it "that night" when somebody dug up Ali's grave. Wilden could have thought there was evidence against him in there, and it would be the PERFECT crime for him to have been involved in digging up Ali's body; nobody would suspect him, especially because whoever did it "ruined" his investigation plans. He could have figured out that Ali wasn't dead at this point, and put together that someone knew what he had done to Ali. This could be why he was killed; remember, CeCe told Holbrook that if she did kill Wilden, maybe she had a good reason for doing it.
--Jenna said that Wilden saw Alison on the night of her disappearance and that she found this out from Garrett. Perhaps Jenna and Garrett were also protecting Wilden when they planted that "I know what you did" note on Jason. Wilden also would have known how easy it would be to pin the crime on Jason because he was drunk and high and didn't remember anything about what happened.
--Wilden has pointed out numerous times that Hanna is very similar to Ali. Wilden pretty much threatened to kill Hanna ("either you shut Hanna up or I will!") Obviously Wilden has no problem with threats like this and the idea of hurting the girls. Ali, as mentioned above, was seen numerous times trying to get as much money as she could. Maybe she was trying to drive Wilden out of town the same way that Ashley Marin was.