Doakes

James Doakes is a sergeant serving as lead case investigator to Miami Metro PD's Homicide. Doakes had killer impulses which drove him to divorce his wife, confessing that if he had stayed with her any longer, he would have killed her.
Doakes instinctively hates Dexter; and is the only person in Dexter's life who can see through his mask of normalcy, Doakes suspects that Dexter is hiding something and has no reservations about telling him so. Ultimately, Doakes realizes that Dexter is withholding vital information on the Ice Truck Killer case and his frustration drives Doakes to physically attack him, only for Dexter to expertly fight back. Doakes' friend LaGuerta tells him to back off, but Doakes begins following Dexter in secret.
Doakes temporarily ends his stalking when he finds Dexter attending a Narcotics Anonymous meeting, supposedly for heroin addiction. Doakes erroneously believes Dexter's dark secret is that he is a drug addict whose addiction is caused by work-related stress, Doakes tells Dexter that he has seen many policemen led down the same path. Feeling sympathetic towards Dexter, Doakes briefly leaves him alone.
Doakes resumes the hunt, however, when Debra innocently reveals that Dexter does not so much as smoke. On finding Doakes meddling in his past again, Dexter goads him into a seemingly unprovoked fight in front of the entire squad room. Doakes breaks into Dexter's apartment, and stumbles upon Dexter's blood slide collection box, and realizes Dexter's secret—that he is the Bay Harbor Butcher. Ironically, Doakes is by now the prime suspect in the case, thanks to Dexter's manipulation of the evidence.
Doakes attempts to apprehend Dexter himself in the Everglades, but Dexter gets the upper hand and locks him in Jimenez's cabin while deciding what to do. Doakes tries to convince Dexter to turn himself in; however, Lila Tournay finds the cabin and blows it up by igniting propane tanks after finding out that Dexter is the Bay Harbor Butcher. Doakes' incinerated remains are found along with the dismembered body of Jose Garza, and so the case is closed, with the official conclusion being that Doakes was the culprit.