Doakes enlisted in the U.S. Army and there earned his nickname "Sane James" for his ability to detect the mentally unhinged.

[2] After spending many years in black operations, Doakes gave up his military career, electing instead to use his skills to help civilians as a police officer.

Doakes's police career grinds to a halt when he receives excessive force citations; his volatile, angry nature proves he cannot work well with others (unless leading them).

Doakes is initially prepared to accept dismissal and take a high-paying security job LaGuerta set up for him, only to begin suspecting Dexter is the notorious Bay Harbor Butcher when Special Agent Frank Lundy mentions shoddy blood work as a reason for the acquittal of one of the Butcher's victims.

Doakes manages to escape from his cage, but he ends up with Esteban and Teo Famosa, drug runners tied to Jimenez.

In the final episode, Angela Bishop, a small town, rural New York police chief and Dexter's ex-girlfriend, decides to call Angel Batista to question him about the Bay Harbor Butcher (Angela looked at old victims of the Bay Harbor Butcher and sees similar injection sites to the ones that two drug dealers, one killed by Dexter, have).

She states he will be arraigned for Matt Caldwell's murder and when Batista arrives, he will be extradited to Miami and be charged as the Bay Harbor Butcher, possibly getting the death penalty.

In the novels, Doakes's first name is "Albert",[6] and he served in El Salvador with the United States Marine Corps Force Reconnaissance .

[citation needed] Dexter believes that Doakes has a "Dark Passenger" of his own, and deals with it by being as violent as he legally can in his job.