Mark also admitted that, while he threw Erin’s bike in the river, it was only because he was scared the police would find the bike and assume he was guilty as a result.

Although it’s left to be seen whether or not Deacon Mark is telling the truth, with Billy and John’s (Joe Tippett) shady behaviour going on elsewhere, it’s seeming more and more likely that he didn’t actually have anything to do with Erin’s death.

Did Billy really kill Erin?

The big question at the heart of episode six is whether or not Billy is really telling the truth about being Erin’s murderer. If the rumours about his and Erin’s relationship are true, it certainly makes sense, but it seems like something more could be at play here – especially when it comes to Billy’s brother John.

Not only did John insist that Billy confess to Erin’s murder out loud as if to convince himself of something that’s not true, but he also asked his wife to keep Billy’s crime secret from Mare and acted shifty when she was asking the family questions about their Lake Harmony reunion, where Billy and Erin are rumoured to have first hooked up.

Then there was the fact that, on the receipt for Erin’s ‘5-29-17’ necklace, the name “Ross” is listed. Is it possible that John could have bought that necklace for Erin? That he, and not his brother, was the one having a relationship with Erin?

Even if this isn’t the case and Billy is the one who dated Erin, then John’s shifty behaviour hints to the fact that he at least had something to do with her murder. Perhaps he killed Erin to protect his brother, and Billy is covering from him? Or maybe the pair murdered Erin together?

Mare Of Easttown episode 6 recap: 8 big questions that need answering during next week’s finale