Who Is "The Professor" on The Perfectionists? Breaking Down the Most Likely Suspects

Updated on May 25, 2019 at 12:30 PM

The Perfectionists first premiered in March, and it's just as dramatic as Pretty Little Liars. After getting well-acquainted with the brilliant and beautiful students of Beacon Heights University, we quickly learn that not everyone is as perfect as they appear. Ava (Sofia Carson) has some major family drama, Dylan (Eli Brown) is keeping a secret from his boyfriend, and Caitlin (Sydney Park) is trying to protect her mother's reputation.

However, at the center of all the drama is the college's resident bad boy, Nolan, who has been blackmailing and lying to all three of the students. Fed up with Nolan's ways, Ava, Dylan, and Caitlin meet up in the woods and joke about how their lives would be so much better if he wasn't around. Interestingly enough, he isn't for much longer — Nolan meets a mysterious person on top of the school's roof and is pushed to his death.

This whole season we've been trying to figure out who the killer is, and just when we've think we've finally figured it out, the series hits us with another curveball. In the season one finale, it's revealed that Nolan's murder is someone called "the professor" and they've been surveilling Ava, Dylan, Caitlin, Alison, and Mona as part of some experiment. So, just who is this mystery person? Let's break down the suspects, from least to most likely, ahead.

Alison

Why She's the Killer:

We can't help but find it a little weird that Alison leaves her life with Emily behind for a position as a TA. Maybe her move to Beacon Heights University is about more than just being a mentor to young students. Is she secretly working with the professor behind the scenes?

Why She's Not the Killer:

Not only does she seem to genuinely want to help her students, but she's one of the OG pretty little liars. If she truly is a killer, wouldn't she have done it by now?
She goes out of her way to help Caitlin, Dylan, and Ava when Dana Booker lists them as suspects for Nolan's murder.
She is one of the people being surveilled by the professor.

Mona

Why She's the Killer:

Let's be real, Mona has always been a little sketchy. She was the first "A" on Pretty Little Liars, after all.
She also has some deep ties to the college and their secret surveillance of the students. Whether it was intentional or not, maybe she helps the professor facilitate Nolan's murder.

Why She's Not the Killer:

Though Mona is a bit unhinged at times, she immediately becomes hell-bent on decoding the school's surveillance software so that she can find Nolan's killer.
She is part of the group being surveilled by the professor.

Dylan

Why He's the Killer:

Nolan was holding a pretty big secret over Dylan's head: that they secretly hooked up while Dylan was in a relationship with Andrew — right before Dylan and Andrew were going to move in together, mind you! Nolan eventually blackmails Dylan to make him do all of his school assignments. Maybe Dylan he finally hit a breaking point and snapped!

Why He's Not the Killer:

It definitely seems like Dylan has some unresolved feelings for Nolan, so we doubt that he would actually kill him.
He is the first person to jokingly suggest to Ava and Caitlin that they should kill him. That would kind of give him away, no?
He is part of the group being surveilled by the professor.

Ava

Why She's the Killer:

After Nolan cheats on Ava with another girl, it's possible that Ava wants revenge. Not to mention, she could be holding some resentment for having to keep their relationship a secret all this time.
Ava later tells Caitlin and Dylan that she followed Nolan to an abandoned cabin before he was killed. What else is she keeping a secret?

Why She's Not the Killer:

Even though she is hurt about their breakup, she is pretty shaken up by his death. Deep down, it's clear that she and Nolan really did care about each other.
She is also part of the group being surveilled by the professor.

Caitlin

Why She's the Killer:

The way Nolan dies is the exact way Caitlin fantasizes about killing him in the woods. Coincidence? Maybe not.
Nolan was also blackmailing Caitlin with photos of her mother cheating on her other mom. If the photos were to leak, it could ruin her mom's entire political career. Maybe she's doing all of this to protect her family's reputation.

Why She's Not the Killer:

It seems a little too easy that the person who predicts how Nolan will die is actually the killer.
She is being surveilled by the professor.

Jeremy

Why He's the Killer:

After finding out that Caitlin logged into his computer, he goes to extreme measures to make sure it's destroyed. Clearly he has something to hide.
Taylor finds out that Jeremy was secretly stalking Nolan when he was alive.
After Taylor shoots Jeremy, it is revealed that he has been secretly working with the professor this whole time. Perhaps he is the one who did the dirty work?

Why He's Not the Killer:

Based on what the professor says about the experiment, it seems like Jeremy is a small piece in a much bigger puzzle.

Taylor

Why She's the Killer:

Taylor already has a bad track record, given that she fakes her own death. Maybe she didn't want anyone else to know she was alive, so she decides to kill the only person who knows her secret: her own brother.

Why She's Not the Killer:

Right before Nolan falls off the roof, he tells the killer that Taylor is alive. Why would he tell his sister what she already knows?
Taylor is pretty shaken up when Jeremy is accused of murdering Nolan. She even goes as far as to shoot him when he tries to get away. We doubt she would do this if she was indeed the killer.

Mason

Why He's the Killer:

As Alison points out, Mason reacted strangely to Nolan's death. He went from sobbing at his funeral to trying to take his place the next day in class. Perhaps Mason was always jealous of his best friend and decides to kill him so he can have his life.
It's eventually revealed that Mason and Claire had an affair shortly after Nolan's death. Perhaps he was working with Claire to kill him.

Why He's Not the Killer:

While the evidence against him is a little suspicious, it almost seems a little too obvious that Mason is the killer.
Following his affair with Mona, it's clear the he has developed true feelings for her. It seems unlikely that he would blackmail her.

Claire

Why She's the Killer:

It's obvious that Claire isn't being completely honest with her son. After she suspects that he is lying to her about his relationship with Ava, she orders campus security to put extra surveillance on her son. When Taylor and Nolan meet in the abandoned cabin, on the other hand, they seem pretty adamant about proving that the campus is using their technology for just that. Perhaps Claire catches wind of what her son is doing and decides to put a stop to it once and for all.
She seems a little too calm when "the perfect posse" claim that Jeremy is the one who murdered Nolan. Perhaps because this clears her name?
Shortly after Taylor shoots Jeremy, Claire has her sent away to a "retreat" against her will. If she's willing to send her own daughter away, what is she willing to do to her son?

Why She's Not the Killer:

We'd like to give Claire the benefit of the doubt that she wouldn't actually murder her own flesh and blood.