Markham is a former federal agent of the United States Customs Service. Markham was responsible for the arrest of drug lord Carter Verone working alongside Monica Fuentes, a fellow former Customs agent.
Markham worked with Monica Fuentes as her handler when she went undercover infiltrate Carter Verone's drug operation. Fuentes and Markham meet discreetly, exchanging information for over a year before Bilkins and the FBI became involved with Verone's case.
2 Fast 2 Furious
When Fuentes exposes Brian O'Conner, an ex-cop turned illegal street racer, to the authorities, Markham appears near the tail end of the police pursuit driving Crown Victoria. Brian, driving the 1999 Nissan Skyline GT-R R34, evades him until Markham used an EDU launcher. EDU shorted out the operating system on the car, allowing the police to apprehend Brian.
Following Brian's arrest, Markham explains to Brian their operation to bring down Carter Verone that consequently put fellow U.S Customs Agent Monica Fuentes undercover. Though Bilkins doubted her trustworthiness Markham is assured that she is still trustworthy. Markham, however, strongly opposes the inclusion of Brian, but has little choice in the matter but to trust Bilkins.
Following the recruitment of Roman Pearce, Markham's mistrust of Brian grows stronger. When the two engage in a test conducted by Verone, Markham assumes the two are running. He uses the GPS installed in both the Spyder and Evo to corner them, but the concealed weapon Rome carried with him during the test, prevented him from arresting them.
He attempted to arrest Roman for attempting to shoot a federal agent, which caused a brawl to erupt between the two of them; Roman and Brian consequently blame him for nearly blowing their cover. Markham also inadvertently blows Monica's cover after sending in a SWAT team to the airstrip she told him about based on false information Verone told her to test her, despite Brian imploring him to wait. Markham does, however, eventually trust Brian and Roman after they successfully stop Carter Verone from the fleeing the country.