Blue Bloods

CBS | 10:00 pm

Following the murder of the key witness in a case Danny (Donnie Wahlberg) was working, Erin (Bridget Moynahan) puts Anthony (Steve Schirippa) on a search for the killer — to Danny’s very obvious chagrin — in "Guilt by Association." Schrippa’s fellow "The Sopranos" veteran Michael Imperioli returns as federal attorney Robert Lewis, who wants Frank’s (Tom Selleck) cooperation in an excessive-force probe. Will Estes and Vanessa Ray also star.