The series follows the Reagan family of police officers with the New York City Police Department (NYPD). Francis Xavier “Frank” Reagan is the Police Commissioner. Frank’s oldest son Danny is a NYPD detective, his youngest son Jamie is a NYPD police officer, and his daughter Erin is the assistant district attorney. Frank’s middle son Joe was murdered in the line of duty in events that pre-date the series, when he was involved with the Federal Bureau of Investigation (FBI) investigating a group of corrupt NYPD cops. Frank’s father Henry is a former NYPD beat cop who rose through the ranks to Police Commissioner. Both Henry and Frank’s wives are deceased. Erin is divorced and has one teenaged daughter, Nicky, who lives with her. Danny is married to Linda, an ER nurse, and they have two sons, Jack and Sean. Jamie is unmarried. A show signature is the Sunday dinner scene around the large table in Frank and Henry’s home. The four generations of Reagans gather to eat and discuss their week, which naturally includes current cases or controversies depicted in each episode. The grandchildren often have meaty or moral issue questions which the various adults answer, sometimes with differing viewpoints. The conversation may also include family members ribbing each other, and Henry or Frank dispensing wise advice. Sometimes the conversation breaks down in acrimony because of differing feelings or perspectives among family members on emotional issues, but the family always remains loving and united.