Part of the dark joy of the cozy crime show Only Murders in the Building is playing along with the investigation. As Mabel, Charles, and Oliver sneak around New York City and their lavish Arconia home, viewers are at their side, noting every clue and inconsistency as the threesome interrogates suspects. With the finale for Season 3 just around the corner, this tenacious trio thinks they've found the killer of Ben Glenroy. But we at Mashable think they've gotten it wrong.

Let us step you through the clues that have led us to not one suspect, but two.

First, let's discuss the revelations of episode 9, "Thirty."

Mabel and the boys suspect Donna DeMeo.

Cliff, Donna, and Howard watch a "Death Rattle" rehearsal. Credit: Hulu

Having learned from Dickie Glenroy (Jeremy Shamos) that his brother was poisoned on opening night, Mabel (Selena Gomez), Oliver (Martin Short), and Charles (Steve Martin) determine a Schmackary's cookie topped with poison must have been the murder weapon.

They believe swaggering, oft-drunk producer Donna (Linda Emond) used her connections to get an advance copy of Maxine's devastating review of Death Rattle; to save the show she had to kill the wooden leading man. A dash of rat poison sprinkled on his favorite "weakness" would do the trick.

However, what if it wasn't Donna who did it? After all, it was her "boy" Cliff (Wesley Taylor) who tried to hand Ben a cookie. We don't know who saw the review or shredded it, but we do know from Donna that Cliff needed a pep talk ahead of curtain. Death Rattle was to be Cliff's first production, and this nepo baby couldn't cope with it failing. Perhaps this is why — while Cliff has been giddy at the show becoming a musical and potentially bringing in big stars — he didn't seem thrilled when Ben popped up at the cast party decidedly not dead!

Another curious detail that could point to Cliff: Ben specifically asked Cliff to be sure his guests (his secret sewing circle) were all set up in their reserved seats. We never heard from Trixie, Marigold, Emerald, Dot, and Mei Mei why they weren't there opening night. Could it be Cliff interfered to push Ben to the brink — where a cookie would be his only comfort?

I suspect so. And yet, I don't think it was Cliff who killed Ben at the Arconia.

Who pushed Ben to his death?

CoBro No! Credit: Hulu

All season, Charles and Mabel have been looking to the cast and crew of Death Rattle for the answer, questioning the ingenue, the understudy, the stage manager, and even Ben's resentful brother. But what if the killer had access to the theater and was not involved in the production?

I'm talking Tobert (Jesse Williams).

Tobert killed Ben: a theory

Hear us out. Credit: Hulu

Where was Tobert when Ben was killed? We don't know his whereabouts between when Ben took his camera before curtain call on opening night and when Ben was discovered. Here's how I suspect it played out.

Tobert, believing Ben to be dead, sought to recover the last known footage of the movie star alive. Presumably, he'd already checked the dressing room, so he headed to Ben's penthouse at the Arconia. As Tobert would later tell Mabel, he was turning the behind-the-scenes doc he was hired to make into a true crime doc about Ben's murder. However, not knowing Ben had survived his apparent death on stage, Tobert would have been shocked when the CoBro appeared. And Ben probably didn't appreciate finding his hire breaking into his place.

The two likely argued — especially as Ben realized his lusty outburst over cookies was caught on tape — and the end result was Ben falling down the elevator shaft.

Tobert covers his tracks.

Murder board! Murder board! Murder board! Credit: Hulu

Did Tobert mean to kill Ben? Maybe he decided one push would give him a documentary subject that could change his life — by ending another's. Maybe it was an accident, a scuffle that led to death. Maybe Tobert was given an opening night handkerchief, and Ben grabbed it as he fell. Or maybe Ben went up to his suite to wipe his eyes with the gift his sewing circle helped him make and then discovered fresh treachery with Tobert at his door.

Regardless, from that point, Tobert was determined to make his doc, happy to agree with the NYPD's arrest of stalker Gregg (Adrian Martinez). Working on animal docs, he has been toiling in obscurity, but now he could jump into the true crime trend that has made a star out of many a nobody, including "Bloody Mabel." When Mabel makes clear she is on the case, he buddies up to her, much like the killers in Seasons 1 and 2 did to throw the central trio off their scent. He gets so in the mix that he even messes with her murder board — and perhaps leaves a clue behind? Could it be Tobert's handwriting on that card will be tied to the message on Ben's mirror? Maybe the movie star didn't write that; maybe Tobert did to generate some drama for his documentary.

Tobert seemed very eager to push into Ben's dressing room ahead of curtain. Was he looking to catch on tape Ben's reaction to the "fucking pig" graffiti? When Mabel later found him at the Goosebury Theater, he said he was tailing his lead. But was he looking to destroy the evidence on the mirror (which Oliver ended up doing)?

After all, Tobert was a liar from the start. He claimed we'd never hear from him, but he's been slinking in the background all season, somehow avoiding suspicion. When he and Mabel met on the way to Ben's penthouse, he lied about what he was looking for, claiming it was a microphone when it was actually the last known footage of Ben alive. "There's a really interesting story here," he tells Mabel, "And I have unique access to it."

Could that "unique access" be code for "I'm the killer?" We'll find out next week!

Only Murders in the Building Season 3 is streaming on Hulu.