Mare Of Easttown Finale Predictions: Who Killed Erin McMenamin?

Who killed Erin McMenamin? That’s the million dollar question ahead of HBO’s Mare of Easttown Sunday series finale. For those who haven’t watched, Easttown mare stars Kate Winslet as Mare, a local detective tasked with solving the murder of a teenage mother in a Pennsylvania suburb outside of Philadelphia.

Before we go any further, here is your spoiler warning. I’ll be discussing the spoilers, so if you haven’t caught up on your catching up yet or plan to watch the show at some point, stop reading. Easttown mare is a small town murder mystery with an excellent performance by Winslet. I was hooked from the first episode. Ok, let’s move on.

*******Spoilers from now *********

In the penultimate episode, Billy Ross confessed to the murder of his cousin, Erin. Billy’s brother, John, adultery (cheap shot by me?), Decided to take Billy to their father’s cabin on one last fishing trip instead of surrendering. Does Billy aka Fredo come out on the boat?

Mare traced the origins of Erin’s necklace and confirmed that a member of the Ross family had purchased it. Mare ran to the cabin to confront Billy, who she said killed Erin. Mare has good reason to believe that Billy killed Erin. Additionally, Billy hid the gun in the tackle box of his fishing gear that potentially killed Erin. There is also the possibility that Billy fathered Erin’s child.

As Mare ran to the cabin, Jess visited the compound and turned the photo she had taken from Erin’s diary. Chief Carter looked distressed after seeing the photo and urged his colleague to call Mare.


So who killed Erin? Here are the suspects.



He confessed to the murder, right? Billy clearly loved and cared for Erin. There may have been inappropriate and extracurricular activities between cousins. For a show that has had twists and turns at the end of every episode, Billy as the murderer seems way too obvious. Do I think he liked Erin? Yes. Is he hiding something? Yes. But did he kill Erin? No.


Mare’s best friend being the killer is a twist that would elicit a huge backlash on Twitter. On the night of Erin’s murder, Lori was at the bar with Mare to celebrate the anniversary of Mare’s big bang, but it’s unclear where she is later that night. Di Lori kills Erin? Maybe John cheated on Lori with Erin, which led to Lori taking matters into her own hands and killing Erin to save her marriage. I don’t think Lori is the slayer, but she’s hiding a major secret from Mare.

There is a Reddit post who chose Lori as the murderer because of her Dave Matthews Band t-shirt. I want Lori to be the one to do it now.



The word I associate to describe Dylan is shoddy. This guy stinks of cigarettes, alcohol and bad decisions. I’d like to believe he was once a good kid, but good kids don’t threaten teenage girls with a gun to their head. Like most of the characters in Easttown mare, Dylan is hiding a major secret. I don’t believe Dylan killed Erin, but I tend to think he knew the true identity of DJ’s dad. Maybe the Ross family paid Dylan to shut up when he found out the baby was the product of incest. All I know is Dylan probably smells like shit and needs to shower more than twice a week.



Why is Guy Pearce in this show if he’s not the killer? Many believe that Richard was involved in Erin’s murder due to Pearce’s involvement. Pearce is almost too big a star to be an emotional support character with little to do on the show. Why are we all cynical? Can’t Richard love Mare and not have ulterior motives? If you told me Richard had killed in his past life to become a better writer like Sharon Stone in Primary instinct, you might be on to something. Richard didn’t kill Erin because he slept with Mare that night. Pearce could very well be a huge red herring.


Now we cook with gas. John is my boss in the clubhouse of whoever killed Erin. For starters, he cheated on Lori so he’s ready to commit immoral acts. John was at the family reunion that Erin attended and could have bought the necklace for her young cousin. Why would John let Billy confess to murder and respond with a cabin fishing trip? John tells more lies than a phone game. The way Chief looked at the photo was so shocking that it depicts a ‘Mare got the wrong guy’ moment. It must be John… right?



Frank might have seemed to be the “normal” in his relationship with Mare, but he’s just as problematic and twisted as his ex-wife. Who buys a house DIRECTLY BEHIND his ex-wife’s property? Frank once helped Erin by donating baby DJ supplies. Maybe he spent a little too much time with Erin if you know what I mean. If we couldn’t trust Roy to Office, why should we trust Frank?

Deacon mark


Deacon Mark is a strange cat. He received complaints from his former ward about his involvement with children before being transferred to his current post. Deacon Mark saw Erin the night she died. These are his words, not mine. He also threw Erin’s bike into the river. Much like Dylan, Deacon Mark is too obvious a choice, but that doesn’t change his goosebumps.


Siobhan didn’t kill Erin just because of her musical tastes. I refuse to believe that a Boygenius and Phoebe Bridgers fan would kill another human.

So who killed Erin?

Someone must have killed Erin Easttown mare. Here is my theory:

John and Billy loved Erin more than a cousin. John started his affair with Erin at the family reunion. Erin then confided in Billy about her relationship with John, which upset Billy. Erin knew it would never work with John because of her marriage to Lori. Then Lori later found out about this incestual affair but remained silent due to the shame it would bring to her family.

John continued his affair with Erin until she was pregnant with his child. John couldn’t support the baby because it was the product of incest and if this secret became public it would ruin his life. That’s where Dylan comes in. A pregnant Erin had sex with Dylan to make it look like Dylan was the father.

Fast forward to the events that led to his death. After Dylan refused to pay for DJ’s ear surgery, Erin went to John to ask for money. John refused, which led to Erin’s stint as an online prostitute. After being humiliated in the woods, Erin panics and calls Deacon Mark, Billy, and John. After talking with Deacon Mark, Erin meets John in the park and they have sex. Halfway, they stop and Erin begs John to pay for the DJ surgery. John once again refuses. Erin threatens to make their incestuous secret public. The two have an altercation that ends with John murdering Erin.

Where are Dylan and Jess from? This is the only part of my theory that lacks conviction. My gut tells me that Dylan and Jess had a secret relationship. Erin finally found out about the night of the party in the woods. Why would they burn Erin’s journals? Again, I’m not quite sure, but maybe Dylan and Jess believed Erin knew about their affair for a while, so they burn her diaries just in case Erin wrote to this. subject.

After John escapes, Billy arrives at the scene and witnesses Erin’s corpse on the ground. Billy breaks down and hugs her, which explains the blood on her clothes later that night. Billy then panics, knowing that he will be blamed for Erin’s death if anyone spots him. So Billy drives Erin to the cove and leaves her there, hoping someone else will be blamed for Erin’s death.

Billy appears to be an easily manipulated person. After John hears about Billy and the bloody clothes, John decides to force Billy to confess to Erin’s murder. Since Billy can no longer take the guilt, he confesses to the murder right in front of John. Mission accomplished.

However, John believes Billy will tell the truth about his brother’s relationship with Erin and admit he didn’t kill her when it comes time to discuss things with Mare and the police. John can’t take this risk so he takes Billy into the cabin to kill him.

End of the scene.

Hopefully we get all the answers we need on Sunday night.

What are your predictions for the Mare of Easttown final? Leave your thoughts in the comments below or tweet us, @danny_giro.

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