Fallen

S5 E6: A picture perfect family is shot dead in their home and the team goes in search of a drug dealer with a likely connection. Voight (Jason Beghe) asks for the help of Vice Sergeant Sean McGrady (guest star Wil Traval) who has an old beef with Upton (Tracy Spiridakos). When McGrady turns up dead during the investigation, the case takes an unlikely turn.