Walter Monroe was a serial killer of prostitutes in Miami that James Doakes was trying, but unable to arrest. Sooner or later, Monroe disappears, much to Doakes' anger. When Doakes later tells Dexter Morgan his resentment in dating Maria LaGuerta, the latter tells him: "Never jump the fence if you're not willing to face what's on the other side", a quote directly from Monroe's diary, which is locked up in Doakes' drawer ever since he obtained it from a search warrant. A possible explanation is that Monroe said this to Dexter in his final moments - "a friend said it to me in a moment of stress."