FBI

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.

A number of times in the series the agents assume someone is their suspect because they have the same caliber gun as the murder weapon, and its almost always a 9mm. Yet the 9mm is by far the most common handgun caliber in the world, so arresting someone based only on the fact that they own a 9mm is something that would not actually happen, it is the weakest kind of circumstantial evidence.