The story in this episode about the gunshot victim at a Halloween party has striking similarities to how actor Anthony Lee (guest star in Season 7 Episode 7 titled "Rescue Me") died. The actor was shot by LAPD Officers who thought he had a weapon, but he in fact only had a toy gun and not a real weapon. Unfortunately he did not recover from his injuries and died (the episode he appeared in was dedicated to his memory when it first aired).
Gregg Henry (who guest stars as Officer Mark Downey) will later star as Dr David Downey in another Medical Chicago-based TV Series, Chicago Med.
The officer tells Cate, "You sound like a cop". Many years later Angela Bassett would go on to play a police officer in 9-1-1 (2018).