Darwin was the pet Chimpanzee of Ian Blackburn. On the day of Blackburn's death, he was brought along with Blackburn to the Panic Room, where Wolff lay in wait. Darwin then jumped Wolff, having sensed that he was trying to kill Blackburn, but Wolff ultimately killed his owner, leading Darwin to become fearful of bald people. Wolff was forced to frame Darwin with the murder, because his attempt at making his death seem like a suicide was ruined. This eventually led Darwin to nearly be put down, especially when he was eventually demonstrated to have at least some knowledge of firing a gun while Stottlemeyer tried to interrogate him, although Sharona, suspecting the chimp's innocence in the murder, rescued him from the shelter, leading to her arrest in the process. Monk was then forced to keep the monkey in his apartment (Sharona had placed the chimp in the apartment without his knowledge). Monk eventually deduced what had really happened after Darwin panicked at Monk's landlord's bald head. Darwin was then placed into the San Francisco Zoo, with the bald member of Animal Control also wearing a cap whenever in Darwin's presence after learning of Darwin's fear of bald people.