Oldest son Danny (Donnie Wahlberg) is an NYPD detective who confronts dangerous criminals, generating suspicions about his own methods and practices along the way. His brother, Jamie (Will Estes), a graduate of Harvard Law School, serves alongside his family as a beat cop. Meanwhile, their sister Erin (Bridget Moynahan) juggles her duties as both a devoted single mother and an ambitious Assistant D.A. At the forefront of it all is patriarch and Police Commissioner Frank Reagan (Tom Selleck), determined to hold his family together despite the turmoil of personal drama, criminal threats or internal allegations. Throughout these four riveting seasons of Blue Bloods, Frank and his family prove that it will take more than a professional or political crisis to tear the Reagan family apart.