Frank Reagan is the Police Commissioner of New York and head of the Reagan clan. He tries to run his department in the same diplomatic manner he runs his family, even when dealing with the politics that plagued his father during his stint as Chief.

Frank's eldest son Danny is a seasoned detective and family man who, at times, uses dubious tactics to investigate his cases. The sole female in the family is Erin, an Assistant District Attorney and newly single mother, who also serves as the legal compass for her siblings and father.