Dick Wolf had been pitching a series focusing on the FBI to NBC for ages hoping to spin it off from La ley y el orden: Unidad de Víctimas Especiales (1999). However, NBC did not go through with the idea, so CBS quickly snapped up Wolf's idea and it became his first series not to air on NBC.
At least four actors in the pilot (Jeremy Sisto, Connie Nielsen, Dallas Roberts, and Alana de la Garza) appeared in previous Dick Wolf shows. Jeremy Sisto played a detective on La ley y el orden (1990). Connie Nielsen appeared as a detective on La ley y el orden: Unidad de Víctimas Especiales (1999). Dallas Roberts played a criminal that crossed over Chicago P.D. (2014) and La ley y el orden (1990). Also, Alana de la Garza played an assistant district attorney on Law & Order.
Actor Zeeko Zaki shares the same backstory as his character Omar Adom "OA" Zidan, both were raised in New York and they are both fluent in Arabic and English. Zaki mentioned that series creator Dick Wolf encouraged him to speak to the shows production crew about developing OA's background after he was cast as a Muslim-American FBI agent. In fact Zaki jumped at the chance to do the series as he has said in an interview for a Time opinion piece, that being cast as an FBI agent was his way to contribute against stereotyping that all Muslims (regardless if they're from places that have a Muslim majority or not) are bad people.
Running Total of Actors from other Dick Wolf projects:
- Jeremy Sisto from La ley y el orden (1990)
- Connie Nielsen from La ley y el orden: Unidad de Víctimas Especiales (1999)
- Dallas Roberts from La ley y el orden: Unidad de Víctimas Especiales (1999) via Chicago P.D. (2014)
- Alana De La Garza (Most Wanted (2019) which was expected till a last-minute re-jiggering) from La ley y el orden (1990)
- Tracy Spiridakos from Chicago P.D. (2014)