The following contains spoilers for Only Murders in the Building Season 3, Episode 8, "Sitzprobe," now streaming on Hulu.
Only Murders in the Building is back for its third season, with plenty of new twists, turns, and characters. With Ben Glenroy (Paul Rudd) officially dead, Charles (Steve Martin), Oliver (Martin Short), and Mabel (Selena Gomez) reignite their podcast to figure out who the killer is this time. The list of potential suspects is quite long.
After Ben's second death, Mabel uncovers a clue about the murderer's identity in Only Murders in the Building Season 3, Episode 2, "The Beat Goes On." Ben was holding one of the custom handkerchiefs he gave out to the cast and crew of Death Rattle. Since Ben's was stolen by his stalker, Gregg, the handkerchief probably belongs to the killer, meaning it's someone involved in the play. Episode 8, "Sitzprobe," also confirms that Ben was poisoned, so whoever killed Ben had to do it twice and cover up the first attempt.
Updated on September 19, 2023, by Madeline Matsumoto-Duyan: This list has been updated to reflect new revelations about each Only Murders in the Building Season 3 suspect from the latest episode.
11 Cliff
In Only Murders in the Building Season 3, Cliff is Death Rattle's producer alongside his mother, Donna. While he's quite worried about the effect that Ben's death will have on the show, he also seems understandably put out that Ben can't remember his name. Cliff has a lot to lose with Ben's death, but considering how difficult the star can be and his disregard for Cliff as a person, the two likely didn't have a great working relationship.
With Oliver now adapting Death Rattle into a musical, Cliff has decided to stay on as producer, even if it means losing more money, because he genuinely loves the material. He even called in a favor from Matthew Broderick when Charles temporarily dropped out. Cliff would probably be in more of a hurry to leave if he were the killer.
10 Donna
Donna is Cliff's mother and fellow producer in Only Murders in the Building's third season. She appears to have had a better relationship with Ben than her son, but Donna also seems like the type of mom to help her son with anything he asks -- even covering up a murder. But Donna could've had her own reasons for wanting to kill Ben.
After Ben's first supposed death, Donna is quick to pull the plug on Death Rattle, insinuating that Oliver might be bad luck. Donna could've wanted to end the show as soon as possible to save her professional reputation, and the death of the lead could be one way to it. That said, Donna chooses to stay on as producer alongside her son even when she has the chance to leave, making her a less likely suspect.
9 KT
Only Murders in the Building Season 3 introduces KT as the stage manager at the Goosebury Theater. Like everyone else, KT has faced Ben's scrutiny. In her case, Ben got upset at KT for eating his mangoes, which were part of his strict diet. That said, she seems to have liked him well enough.
In Season 3, Episode 6, "Ghost Light," Howard claims that he couldn't sweep on opening night because KT's office, where he keeps the broom, was locked, but KT says she never locks her office. KT could be lying to cover her tracks, but considering how much respect she actually has for theater and its traditions, it doesn't seem likely she'd kill the show's star.
8 Jonathan
Making his debut in Only Murders in the Building Season 2, Jonathan is a Broadway actor and a resident of the Arconia. While last season featured his budding romance with fellow resident Howard, this season dips into his professional life. Jonathan returns as Ben's understudy in Death Rattle, and while he doesn't appear to be a likely suspect, he leads the trio to some crucial information.
In Only Murders in the Building Season 3, Episode 5, "Ah, Love!" Tobert invited Mabel out to watch Jonathan perform at a local cabaret. After his performance, Jonathan met with Ben's personal doctor, Dr. Hiram Camareri, a man Tobert claims many celebrities go to for various medications. Episode 6, "Ghost Light," confirms Jonathan was seeing Dr. Camareri for drugs to help with his anxiety, receiving a concoction that Ben was also taking before he died.
7 Bobo
Little has been revealed about Bobo, which might just make him Only Murders in the Building's biggest wildcard this season. Out of Death Rattle's cast members, Bobo is the most unassuming. He seems to have admired Ben and is shown crying and eating popcorn at his funeral. That said, he could have a dark side waiting to be revealed.
Although Ben doesn't reveal what Bobo asked him, he says that he's constantly telling Bobo "no." Ben vows to stop doing this, but the damage may have been done by that point. Even with Ben's apology, Bobo could've been waiting for the right time to strike. Alternatively, he could just be a genuine admirer.
6 Ty
Not much is known about Ty, apart from the fact that he was one of Ben's co-stars in Death Rattle. Ty incurred Ben's wrath by asking to use his trainer, for which Ben apologized and also claimed that Ty probably couldn't afford him anyway. While Ty brushed these comments off, they could've had a deeper impact than Only Murders in the Building has shown.
Gregg suggested Ty was a schemer waiting for his chance in the limelight. Then again, Gregg also thought Charles killed Ben, so his judgment probably shouldn't be trusted.
5 Kimber
Kimber is another of Ben's co-stars and appears to have been his love interest both on and offstage. At the party, Ben apologizes to her for messing things up between them and promises to make it up to her. According to the footage Mabel and Tobert discover, Ben appears to have been in a romantic relationship with his killer. "Grab Your Hankies" revealed that Kimber was missing her hankie, but Season 3, Episode 4, "The White Room" provided more answers.
Despite appearances, Kimber wasn't romantically involved with Ben. She had asked him to endorse her skincare products, and while he initially agreed, he backed out at the last minute. Kimber then sold her handkerchief on eBay out of spite, but she now regrets it. As expected, it seems Kimber isn't the killer in Only Murders in the Building Season 3 after all.
4 Joy
Joy is Charles' girlfriend who just moved in with him and does makeup and hair on Brazzos. In "The White Room," she claims to have defended Charles from Ben Glenroy, raising suspicion about exactly how she did this. Later in the episode, Kimber reveals Ben called a makeup artist, Joy, to help him cover up a red mark on his face on opening night. Mabel and company then find a mean message on the mirror in Ben's dressing room written in Joy's lipstick.
As damning as this initially seems, in "Ah, Love!" Joy claims she did not write anything on Ben's mirror. She also learns that Charles punched Ben on opening night, resulting in the red mark. Although she's now been cleared of suspicion, Joy's relationship with Charles may be done for good.
3 Loretta
Out of everyone, Meryl Streep's Loretta appears to have had the most strained relationship with Ben. Ben initially wanted her fired, and as she reveals in Episode 5, "Ah, Love!" they had a fight on opening night, after which she wrote "fucking pig" on his dressing room mirror. In Only Murders in the Building Season 3, Episode 8, "Sitzprobe," Loretta is revealed to be Dickie's birth mother and confesses to Ben's murder when the trio and the police start to suspect Dickie.
Despite her confession, it seems more than likely that Loretta is not Ben's murderer. She simply doesn't want her son to go to jail, guilty or not, and she's willing to risk everything to protect him. Loretta also seemed surprised when Dickie told her how he really felt about Ben and his death, so she may even suspect him of being Only Murders in the Building Season 3's killer.
2 Dickie
As Ben's manager and brother, Dickie was constantly at the star's side. Dickie bore the brunt of Ben's demanding attitude, but he still loved his brother and broke down when he went to clean out Ben's apartment in Only Murders in the Building Season 3, Episode 3, "Grab Your Hankies." He's now managing Loretta, but it turns out he had plenty of reasons to despise Ben.
Episode 7, "CoBro," revealed that Dickie cleaned up a lot of Ben's messes over the years without any recognition. Mabel and company believe that Dickie was the true creator of CoBro and may have harbored some resentment about Ben stealing his idea. He also refused to tell Mabel who called Ben the night he died and bought back Ben's bloody handkerchief from Uma. In Episode 8, "Sitzprobe," he admitted that he felt free when Ben died. Finally, the police revealed someone covered up Ben's poisoning, and Dickie might be one of the only people who could've pulled that off.
1 Tobert
Only Murders in the Building Season 3's Tobert is a documentarian whom Ben hires to make a movie about his Broadway debut. He is notably absent from the opening night party in Episode 1, "The Show Must…" Tobert then shows up at Ben's apartment in Episode 3, "Grab Your Hankies," where he and Mabel uncover Ben's troubled relationship with a mysterious figure.
In Episode 5, "Ah, Love!" Tobert invites Mabel on a date under the guise of investigating a lead. Although their running into Ben's personal physician, Dr. Camareri, appears to be a coincidence, Tobert then follows Mabel to the theater and sets her up with proper equipment when she strikes out on her own. Although he's absent from Episode 8, "Sitzprobe," Mabel does point out that previous Only Murders in the Building killers have inserted themselves into the investigation, much like Tobert has throughout Season 3. His motive remains unclear, but there's something fishy about Tobert.