After Emily Harrison tells Danny and Baez she's concerned her abusive ex-boyfriend will repeat his behavior with his new girlfriend, Emily becomes the prime suspect when he's murdered. Also, Eddie gets jealous when Jamie lets a young woman crash at his apartment, and Frank must decide how to discipline a sergeant after he fails to intercede during an armed robbery while off duty,
Elenco: Tom Selleck , Donnie Wahlberg , Bridget Moynahan , Will Estes , Len Cariou , Sami Gayle , Marisa Ramirez , Abigail Hawk , Vanessa Ray , Gregory Jbara , Robert Clohessy , Andrew Terraciano , Amy Carlson , Jennifer Esposito , Steve Schirripa .