Lester's death - and the culprit behind his murder - has introduced many theories about Only Murders in the Building season 5. The fourth finale, which concluded in October 2024, followed Mabel (Selena Gomez), Oliver (Martin Short) and Charles (Steve Martin) as they tried to track down what led to Sazz's (Jane Lynch) murder. They were able to figure out how her stunt prodigy, Marshall (Jin Ha), stole Sazz's script and killed her to keep it quiet.