Who Was Joe Reagan on ‘Blue Bloods’? And How Did He Die?

In Season 1, the Reagan family was still struggling to pick up the pieces a little more than a year after Frank’s (Tom Selleck) eldest son, Joe, was killed in the line of duty. Joe, who was working as an NYPD detective at the time of his death, was murdered by an organization of corrupt cops. 

We learn the truth about Joe’s death in Episode 22, “The Blue Templar,” after Frank’s youngest son’s life was threatened by the same organization. 

Joe’s murderer, Sonny Malevsky (Michael T. Weiss), was later caught by the Reagans and died by suicide, but it’s clear that Commissioner Reagan never really recovered from his son’s death. And things have only gotten more complicated now that the family has discovered Joe Reagan’s estranged son, Joe Hill.

We previously saw that the elder Joe learned that his girlfriend, Paula Hill (Bonnie Somerville), was expecting a child before his death. In an attempt to disassociate her son from the Reagan family, Paula gave the younger Joe her maiden name. But she couldn’t stop him from joining the force.