Captain Donald Cragen (Dann Florek) says, "Every unhappy family is unhappy in its own way." This is a reference to the opening line of Lev Tolstoy's 1877 novel "Anna Karenina," which begins, "All happy families are alike; each unhappy family is unhappy in its own way."
Danny Mastrogiorgio has played four different roles over the course of the series:
- Episode 16.7 Chicago Crossover (2014) - George Turner
- Episode 13.14 Home Invasions (2012) - Mr. Fisher
- Episode 10.4 Lunacy (2008) - Orlando McTeer
- Episode 2.6 Noncompliance (2000) - Earl Miller / Gilmore