Only Murders in the Building Season 3: Killer, Cast, Recap

Selena Gomez, Steve Martin, and Martin Short return for Only Murders in the Building Season 3, cracking a Broadway murder mystery with Paul Rudd as the doomed star. The trio—three strangers who bond over true crime—faces their most personal case yet when the victim is one of their own co-stars. If you’ve been hunting for the full spoiler breakdown, here’s everything verified and explained.

Premiere Date: August 8, 2023 · Platform: Hulu · Episode Count: 10 · Setting: Arconia apartment building · Main Stars: Selena Gomez, Steve Martin, Martin Short

Here’s how the key details stack up for the season.

Who’s the killer in Only Murders in the Building Season 3?

The killer of Ben Glenroy is Donna and Cliff DeMeo, the parents of the Pickwick triplets. According to Den of Geek’s detailed recap, they poisoned Ben with bicarbonate of soda to save their son’s play from being cancelled due to Ben’s erratic behavior. Donna DeMeo is portrayed by Linda Emond, while Cliff DeMeo is played by Jeremy Shamos.

Identity revealed

The killer reveal does not come until the finale episode “Sitzprobe.” Throughout the season, the trio suspects various characters—including the Pickwick triplets themselves and Broadway cast members. The Betches recap confirms that the real killer is revealed only in the finale. The entrapment happens on opening night of the play, with the trio staging a performance to draw out the murderer.

Motive breakdown

Ben Glenroy’s death occurred on stage during a performance of Death Rattle. The DeMeos feared Ben would destroy the play entirely, forcing its cancellation. By poisoning him with bicarbonate of soda, they believed they could control the situation and protect their son’s Broadway debut. The Pickwick triplets are key to the plot involving the killer, as their connection to the DeMeo parents becomes the thread that unravels the mystery.

What happened in season three of Only Murders in the Building?

Season 3 centers on Ben Glenroy, an actor played by Paul Rudd, who collapses on stage during the opening night of the Broadway play Death Rattle. Rotten Tomatoes describes the trio investigating murder behind Broadway show scenes. The season involves the trio drifting apart as Charles and Oliver focus on producing the play while Mabel investigates independently.

Plot overview

The main trio—Charles (Steve Martin), Oliver (Martin Short), and Mabel (Selena Gomez)—investigate murders in the Arconia building, but this season their podcast partnership fractures. Mabel partners with documentarian Tobert, played by Jesse Williams, to investigate Ben’s murder and develops a romance. She also produces a solo podcast episode, which visibly upsets Charles and Oliver.

Key events

According to Wikipedia, the trio makes amends with the cast and crew while investigating. The season builds to entrapping the killer on opening night, with lies among the trio and a killer living among them. The Fandom Wiki notes that the killer entrapment happens during the final performance.

Who dies in season 3 of Only Murders?

The primary death in Season 3 is Ben Glenroy, the Broadway star played by Paul Rudd. His death occurs on stage during a performance, collapsing dramatically during the opening night of Death Rattle. The show’s premise involves three strangers sharing an obsession with true crime who suddenly find themselves wrapped up in one, as noted by Rotten Tomatoes.

Major deaths

Ben Glenroy’s on-stage collapse marks the central tragedy of Season 3. Unlike previous seasons, the murder happens during a theatrical performance, adding a meta layer to the investigation. The Betches recap confirms Ben’s death occurs on stage during a performance.

Circumstances

The circumstances point to poisoning—specifically bicarbonate of soda administered by Donna and Cliff DeMeo. Their motive stems from protecting their son, one of the Pickwick triplets whose play would be ruined by Ben’s problematic behavior. The poisoning is revealed as premeditated, though the full extent of the DeMeos’ planning remains somewhat unclear in the narrative.

Who does Mabel date in Only Murders in the Building Season 3?

Mabel develops a romance with Tobert, a documentarian played by Jesse Williams. According to Den of Geek’s recap, Mabel partners with Tobert to investigate Ben’s murder, and their professional collaboration evolves into a romantic relationship.

Relationship details

Tobert enters the picture as a documentarian working on a project about the Arconia building and its infamous murders. Mabel’s decision to work with him rather than with Charles and Oliver creates tension within the trio. Their romance unfolds across several episodes as they investigate Ben’s death together.

Episode focus

The Mabel-Tobert storyline receives significant screen time throughout the season, particularly in episodes where their investigation overlaps with the trio’s broader podcast work. The romance subplot adds emotional stakes to Mabel’s journey while maintaining the show’s signature blend of mystery and character-driven storytelling.

Only murders in the building season 3 cast

The main trio returns with Selena Gomez as Mabel Mora, Steve Martin as Charles-Haden Savage, and Martin Short as Oliver Putnam. Paul Rudd joins as Ben Glenroy, marking a major casting addition for this season. Supporting roles include Linda Emond as Donna DeMeo, Jeremy Shamos as Cliff DeMeo, and Jesse Williams as Tobert.

Main cast

The core ensemble maintains the chemistry that defines the series. The trio investigates murders in the Arconia building, an exclusive Upper West Side apartment building. According to Rotten Tomatoes, the show’s premise centers on three strangers sharing an obsession with true crime who find themselves wrapped up in an actual murder case.

Guest stars

Season 3 features several notable guest appearances beyond the main cast. Paul Rudd’s role as Ben Glenroy was announced by Variety and marks one of the most high-profile additions to the series. The Pickwick triplets play key roles in the killer plot. As noted by the Fandom Wiki, some cast members from previous seasons did not return for Season 3, creating new dynamics within the Arconia’s resident roster.

Timeline of Season 3

Five key moments anchor the season’s progression from premiere to finale.

What the cast and critics say

“Three strangers share an obsession with true crime and suddenly find themselves wrapped up in one.”

— Rotten Tomatoes official synopsis

“Which of the Pickwick triplets did it? Before the mystery of Sazz Pataki’s murder in season 4, relive Only Murders in the Building season 3.”

— Den of Geek recap

Summary

Only Murders in the Building Season 3 succeeds by shifting the murder mystery from the Arconia’s apartments to the Broadway stage, introducing Paul Rudd as a charismatic victim whose death sets the entire plot in motion. The killer reveal—that Donna and Cliff DeMeo poisoned Ben to protect their son’s play—feels earned after ten episodes of misdirection. The real strength lies in how the season deepens the trio’s fractures: Mabel’s solo investigation and romance with Tobert, Charles and Oliver’s theatrical obsession, and the lingering question of who among them can truly be trusted. With the finale “Sitzprobe” airing September 19, 2023, the stage is set for an even darker Season 4 centered on Sazz Pataki’s murder. For Hulu subscribers, the choice is straightforward: watch the complete season now, or risk the internet spoils before you do.

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The ensemble of Steve Martin, Martin Short, and Selena Gomez anchors season 3’s twists, with their full complete seasons 1-5 roster spanning all episodes detailed here.

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