Frank Reagan often states, "I'm the police commissioner. I know everything." In the Jesse Stone films, in which Tom Selleck also stars, Jesse Stone frequently states, "I'm the police chief. I know everything."
Filming nearly relocated from New York City to Toronto, because city and state tax credit programs had expired. New York State offers a program, which provides qualifying film and television productions a 30% credit for qualified production expenditures plus an additional 5% if the production is made in New York City.
Shares cast members with the FX drama "Rescue Me." Andrea Roth, Robert John Burke, Bruce Altman, and Jennifer Esposito all appear in both dramas. Blue Bloods and Rescue Me both take place in New York City, Blue Bloods involving the NYPD, and Rescue Me the FDNY. They come from a pool of "New York Actors". If you have ever watched any Law And Order episodes You can see all those same actors only about 20 years younger. Even some of the Judges on the benches are the same as the Law And Order judges. And a couple of L&O Attorneys are judges.
In Season 4, Episode 8 you can see that Jamie carries a picture of his late brother Joe tucked inside his Police Hat. This also appears to be the same picture of Joe that's shown in the beginning of the show's Pilot episode on Frank's bureau while Frank is getting ready to attend Jamie's graduation from the Police Academy.
In season 1 Frank Reagan is seen carrying a snub nose 38 special with a 2" barrel given to him by his former commissioner father, who got it from his father. Upon close examination of high resolution photos stills, the revolver is a modified Colt 38 special given the "Fitz treatment". Such treatment having orginated with a Henry Fitzgerald who worked at Colt. The barrel was shortened from 4" to 2", the trigger guard opened, and the hammer cut down.
Frank Reagan has four children, three boys and a girl: Danny, Jamie, Joe (who died in the line of duty just before the beginning of the series) and Erin. Interestingly, the only non-cop in the family is also the only daughter, She works as the Assistant District Attorney.