<Li> Marin Ireland as Liz Holder, Stephen's sister </Li> <Li> Patti Smith as Female Doctor </Li> <Table> <Tr> <Th> No . overall </Th> <Th> No. in season </Th> <Th> Title </Th> <Th> Directed by </Th> <Th> Written by </Th> <Th> Original release date </Th> <Th> Prod . code </Th> </Tr> <Tr> <Th> 39 </Th> <Td> </Td> <Td> "Blood in the Water" </Td> <Td> Nicole Kassell </Td> <Td> Veena Sud </Td> <Td> August 1, 2014 (2014 - 08 - 01) </Td> <Td> BDH401 </Td> </Tr> <Tr> <Td_colspan="7"> Sarah Linden and Stephen Holder deal with the aftermath of her killing James Skinner, the serial killer who was also their boss and her lover . Holder plans a cover - up--he lies to Carl Reddick about their whereabouts at the time; she tells Adrian Seward that Joe Mills killed his mother . While Reddick must officially close the serial killer case, Holder and Linden investigate the murders of the Stansbury family and a survivor, Kyle, the son suspected of the murders whose apparent attempt to also kill himself failed . Holder and Linden question Colonel Margaret Rayne, the superintendent of Kyle's military academy, who believes Kyle is incapable of violence . Holder's girlfriend, District Attorney Caroline Swift, discloses that she is pregnant . </Td> </Tr> <Tr> <Th> 40 </Th> <Td> </Td> <Td> "Unraveling" </Td> <Td> Lodge Kerrigan </Td> <Td> Dan Nowak </Td> <Td> August 1, 2014 (2014 - 08 - 01) </Td> <Td> BDH402 </Td> </Tr> <Tr> <Td_colspan="7"> Linden becomes further unnerved when she learns that Kyle was shot in the same position as was Skinner when she shot Skinner . At the academy, Kyle is bullied by Lincoln Knopf and others . When the detectives question Kyle about his sister, Phoebe, he says she was an exhibitionist, and he had told his parents . Phoebe had punished Kyle for this by cutting his piano wires . Linden, knowing about family dysfunction, believes Kyle; Holder holds him accountable for the murders . Holder and Linden learn about fingerprints in the Stansbury house belonging to Katrina Nelson, who had assaulted the father . They seek to question Kyle about her but are stopped by Col. Rayne, who threatens Linden with a formal complaint . Later, Katrina tells Kyle that his family "got what they deserved". When Reddick questions Linden about Skinner, she admits they had an affair but suggests he ask Skinner about anything more . She then stakes out the Skinner house, watching his daughter, Bethany, who still unknowingly has a ring from one of the victims . </Td> </Tr> <Tr> <Th> 41 </Th> <Td> </Td> <Td> "The Good Soldier" </Td> <Td> Ed Bianchi </Td> <Td> Nicole Yorkin & Dawn Prestwich </Td> <Td> August 1, 2014 (2014 - 08 - 01) </Td> <Td> BDH403 </Td> </Tr> <Tr> <Td_colspan="7"> Linden's slipping sanity forces her to suggest to Holder that they turn themselves in . He mentions Caroline's pregnancy as something he will never lose and suggests Linden move on . When Knopf tells Rayne about Katrina's visit to Kyle, Rayne tries to get Linden involved . Linden then questions Katrina, who gives more insight on the Stansburys and admits to staying in the family beach house the night of the murders . Linden then takes Kyle back to the family home to jog his memory of what happened . He admits to hating his father enough to kill him but doesn't confess to anything . The detectives discover that Kyle's mother, Linda, had been fired from her teaching job for having an affair with Knopf . Holder becomes unnerved when Reddick learns he asked Skinner's wife about the lake house . Reddick even calls him and Linden in when Bethany receives a text from her father . Holder knows Linden still has Skinner's phone . He nearly confesses to the group at his Narcotics Anonymous meeting, where Reddick has an informant . Linden goes to the lake and dumps the phone, as Skinner's wife watches nearby . </Td> </Tr> <Tr> <Th> 42 </Th> <Td> </Td> <Td> "Dream Baby Dream" </Td> <Td> Gregory Middleton </Td> <Td> Sean Whitesell </Td> <Td> August 1, 2014 (2014 - 08 - 01) </Td> <Td> BDH404 </Td> </Tr> <Tr> <Td_colspan="7"> The detectives question Knopf, who admits to having a gun at his parents' house .? However, Holder gets so rude with the mother that she threatens to file a report . Linden asks Holder if he is abusing drugs . At the academy, Kyle must bear a form of initiation from Knopf and his superior, AJ Fielding . At home, Linden finds that her social worker and mother figure, Regi Darnell, has already cooked dinner, although Linden had made previous plans with her son, Jack . Feeling out of control, Linden argues with Regi . Holder later apologizes to Linden . They question Kyle about an injury his mother once received . He replies he broke her wrist when she wanted to become sexual with him . Rayne breaks up the questioning, and the detectives spot a car matching one that had frequented the Stansbury home and was up the road from it on the night of the murders; the car belongs to Rayne . Kyle keeps finding a map of his home with Xs drawn on it and gun . A note is attached, telling him to "Finish what (he) started ." Reddick gathers all the clues that lead him to the lake . Holder calls Linden to also get her there . Red bags containing bodies, and Skinner's car, are being pulled from the lake . </Td> </Tr> <Tr> <Th> 43 </Th> <Td> 5 </Td> <Td> "Truth Asunder" </Td> <Td> Coky Giedroyc </Td> <Td> Dan Nowak </Td> <Td> August 1, 2014 (2014 - 08 - 01) </Td> <Td> BDH405 </Td> </Tr> <Tr> <Td_colspan="7"> As Skinner's body is being looked over, Linden, believing Reddick only has circumstantial evidence, coaches Holder to stay strong and on the same page as her . Holder then sees Kallie Leeds' body in the morgue . Reddick offers his theory to Linden, to which she says he hasn't arrested her yet . He mentions that he dredged the lake because Holder confessed at the NA meeting . At the academy, Knopf tells Kyle to search Fielding's room . There, he finds a map similar to those being left for him . Rayne gives her alibi for the night of the murders, and Linden talks with her about the deaths of a man and his son that led to Rayne's military discharge . Linden visits her mother to ask if she will take care of Jack should something happen to her . They reminisce about Linden's childhood before she was placed in foster care and achieve a form of reconciliation . Linden then sends Jack on an airplane to live with his father . Reddick offers Holder a deal, by saying Linden was spotted at the lake, which led to the dredging . At the academy, Kyle notices similarities for Family Day preparations with the night of the murders . He mentions this to Knopf, who, in turn, tells Fielding at Rayne's house . The three plot to learn all that Kyle remembers . The cadets try to bully Kyle, but he flees to get help from Rayne . Seeing that she could be a part of it, he flees again, while being shot at by the cadets . </Td> </Tr> <Tr> <Th> 44 </Th> <Td> 6 </Td> <Td> "Eden" </Td> <Td> Jonathan Demme </Td> <Td> Veena Sud </Td> <Td> August 1, 2014 (2014 - 08 - 01) </Td> <Td> BDH406 </Td> </Tr> <Tr> <Td_colspan="7"> <P> Holder tells Caroline that he must make a choice--"between me or her ." She knows he means Linden and says only their unborn daughter matters now . Linden gets called and finds Kyle, who's been shot by the cadet search party . He identifies Fielding, Knopf, and Rayne as the murderers . Meanwhile, Knopf suggests killing Rayne, but she mentions cleaning up after them when they stole her car the night of the murders . As the detectives arrive, Knopf and Fielding are shot . Rayne confesses to murdering the Stansbury family, insisting that Kyle be left alone leading Linden to infer that Kyle is in fact Rayne's son who she gave away 17 years previously . Linden wants to use Rayne's confession and arrest her for all the murders, but Holder wants Kyle for the Stansburys' . Frantic, Linden points her gun at Holder, thinking he has worked against her, even with Reddick's investigation . She takes Kyle to his family home, where he becomes aware of committing the murders . Fielding and Knopf were there that night, but left, and Kyle killed his family . At the station, Linden confesses to Reddick having killed Skinner and absolves Holder . Mayor Darren Richmond arrives to squelch the confession . Skinner's death was ruled a suicide, and no killer cop shall tarnish another cop's or Richmond's image . </P> Five years later: Holder and Caroline are divorced, with joint custody of their daughter, Kalia . Linden has been traveling, now that Jack is in college . She apologizes to Holder for not believing in him, as he was her one true friend . She calls Seattle a "city of the dead", intent on leaving it . He hugs her to try to get her to stay with him, but she drives away . However, she later returns to him . </Td> </Tr> </Table> <Tr> <Th> No . overall </Th> <Th> No. in season </Th> <Th> Title </Th> <Th> Directed by </Th> <Th> Written by </Th> <Th> Original release date </Th> <Th> Prod . code </Th> </Tr>

Who killed kyle's parents in the killing