Now Playing: Boyfriend in 'Gone Girl' case describes police targeting

Now Playing: Couple in so-called 'Gone Girl' case on the comparison of their ordeal to the film

Now Playing: Comey says his assumption Clinton would win was 'a factor' in email investigation

Now Playing: US and allies launch attacks on Syria

Now Playing: Iran, Russia should not associate with mass murder of innocent people: Trump

Now Playing: Pentagon officials remark on strikes in Syria

Now Playing: Strikes will establish a strong deterrent of chemical weapons: Trump

Now Playing: Couple drugged and blindfolded, and woman abducted in the middle of the night: Part 1

Now Playing: Police question boyfriend of abducted woman, doubt his story: Part 2

Now Playing: Couple in so-called 'Gone Girl' case denounced by police: Part 3

Now Playing: Man who kidnapped woman in so-called 'Gone Girl' case finally caught: Part 4

Now Playing: California city to settle with couple in so-called 'Gone Girl' case: Part 5

Now Playing: Couple in so-called 'Gone Girl' case convinced more suspects still out there: Part 6

Now Playing: Female trucker says she keeps a knife, mace after being attacked

Now Playing: College student shot dead in Brooklyn neighborhood after night of partying: Part 1

Now Playing: Two men found guilty of murder in college student's shooting death: Part 2

Now Playing: Mom goes 'undercover' on crusade to free her son convicted of murder: Part 3

Now Playing: State witness alleges prosecutor, detectives cut him deal to testify: Part 4

Now Playing: Man's murder conviction overturned after mom's campaign for his freedom: Part 5

Now Playing: Mom still waiting for son to leave jail, despite overturned conviction: Part 6