‘Mare of Easttown’: Who Is the Real Killer in Kate Winslet’s New HBO Series?

Mare of Easttown is HBO’s latest must-watch series. Kate Winslet stars in the gritty crime drama as Mare Sheehan, a police detective in the seen-better-days town of Easttown, Pennsylvania. Mare is a divorced mom who’s struggling to balance her demanding job with her complicated family life. When a young woman is murdered, it sends shock waves through the tight-knit community — and makes things even more complicated for Mare, who must investigate the crime. 

[Spoilers ahead for Mare of Easttown Episodes 1 and 2.] 

What happened to Erin McMenamim in ‘Mare of Easttown’? 

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Most of the first episode of Mare of Easttown focused on introducing the show’s main characters, including Mare, her daughter Siobhan (Angourie Rice), mother Helen (Jean Smart), ex-husband Frank (David Denman), and friend Lori (Julianne Nicholson), as well as, Richard Ryan (Guy Pearce) a novelist and visiting lecturer at a local college who hooks up with Mare after they meet in a bar. 

We also meet Erin McMenamin (Cailee Spaeny). The teenager and her 1-year-old son, DJ, live with her verbally abusive father Kenny (Patrick Murney). She’s broken up with Dylan (Jack Mulhern), her child’s father, and Dylan’s new girlfriend Brianna (Mackenzie Lansing) delights in tormenting her. 

Eventually, we discover that Brianna has been catfishing Erin. She lures the other girl to a local drinking spot, mocks her, and then beats her up. The whole incident is, of course, captured on video. Then, just before the credits roll, we see Erin’s lifeless body in a creek.   

In episode 2, Mare starts investigating Erin’s murder — with some not-exactly-welcome help from outside detective Colin Zabel (Evan Peters). And there’s no shortage of suspects, from Erin’s father to Dylan to Brianna.

Kenny McMenamin

Patrick Murney in profile with eyes closed in Mare of Easttown
Mare of Easttown | Michele K. Short/HBO

Erin’s father Kenny clearly has a temper. He didn’t lay hands on his daughter when they argued about her borrowing his truck and the cost of caring for her son. But it wasn’t hard to imagine him turning violent. 

However, Kenny seemed genuinely distraught when he learned of his daughter’s murder. So distraught, in fact, that he kidnapped the person he believed was responsible, her ex-boyfriend Dylan. Then, he drove Dylan into the woods and shot him in the back as he tried to run away. While it’s possible this is just an elaborate plot to cover up his own guilt, chances are, Kenny didn’t kill his daughter. 

Dylan Hinchey and Brianna Del Rasso

Dylan also seemed like he could be Erin’s killer. (Kenny is obviously convinced of his guilt.) He never wanted Erin to have the baby in the first place and they’d been arguing about the $1,800 she needed for their son’s ear surgery. And when Mare questions him about the attack on Erin, he’s not exactly contrite. But would he go so far as to kill Erin? Maybe, but it seems too obvious that he would be her murderer. 

Brianna’s unprovoked attack on Erin the night she was killed puts her at the top of the suspect list. She’s cruel and violent, and it’s possible that after Erin stumbled away after her beating, Brianna followed her and finished her off. But as with Dylan, Brianna is likely a red herring. 

Frank Sheehan 

david denman sitting at a table in mare of easttown
Mare of Easttown Sarah Shatz/HBO

In episode 2, we also learned that Mare’s ex Frank was one of Erin’s high school teachers. When she asks him about her, he claims not to know her well and says he had a sense there was trouble at home. But his demeanor during that conversation seemed a bit off. Soon, we got a clue as to why.

At the episode’s end, Erin’s friend Jess dropped a bombshell: Erin had told her that Dylan wasn’t her baby’s father; Jess suspects Frank might be the real dad. If that’s true, it certainly gives Frank — who is just about to get remarried — a motive to kill Erin, especially if she was planning to tell others DJ’s dad was her high school algebra teacher.   

Richard Ryan 

One-hit-wonder novelist Richard Ryan just showed up in Easttown, and now Erin is dead. Coincidence? Maybe. He hasn’t done anything particularly suspicious — yet. But how much do we really know about this guy, other than that he has a serious case of writer’s block? He’s definitely one to keep an eye on. 

Deacon Mark Burton

So far, we haven’t seen much of Deacon Mark Burton (James McArdle), but he’s already sending up some red flags. During a conversation with Mare’s cousin Father Dan (Neal Huff), we learned that Erin had once been a member of Deacon Mark’s youth group, but that she stopped attending after her baby was born. Now, there are plenty of good reasons why Erin might have dropped out of the group after becoming a mom. But why bring it up at all if it doesn’t have anything to do with her death? Deacon Mark is sending out bad-guy vibes.  

Only two of Mare of Easttown’s seven episodes have aired so far, and there are still plenty of answered questions. Who is the ferret-like peeping tom spotted in episode 1? Does Mare’s daughter Siobhan know something about Erin’s death? How does Katie Bailey’s disappearance figure into all of this? Perhaps we’ll get some answers — or new suspects — in episode 3.

Mare of Easttown airs Sundays at 10 p.m. ET on HBO.