The series introduces Herc as a detective in the Baltimore Police Department's Narcotics Unit, begrudgingly detailed to the initial Barksdale investigation.

He is generally portrayed as encapsulating the failings of the contemporary Baltimore police officer: simple-minded, concerned with petty street arrests and minor drug charges, and priding himself and his colleagues on banging heads "the Western District way."

Following his promotion to sergeant, he is dismissed from the force, subsequently finding employment as a private investigator for attorney—and invariant legal advisor for drug organizations—Maurice Levy.

Herc and Carver get into trouble early in the investigation when, along with Roland Pryzbylewski, they drunkenly charge into a Barksdale-controlled housing project and harass a group of youths.

Herc is slightly injured when angry residents throw bottles and fire at the officers, but returns early from his sick leave to take part in raids on the Barksdale operation.

When young dealer Bodie Broadus punches Pat Mahon during a raid, Herc, Carver and Greggs give him a beating.

As suggested by Herc, Daniels also brings Carver back but refuses to recognize his promotion; Kima remains the lead detective for the details.

With Carver in charge, they are responsible for running the district's Drug Enforcement Unit and commanding a squad of dedicated plainclothes narcotics cops, including Kenneth Dozerman, Lloyd "Truck" Garrick, Lambert and Anthony Colicchio.

Herc is critical of Colvin's project, especially after rejecting Carver's request to help him move a homicide victim off the free zone premises, and eventually leaks details on Hamsterdam to The Baltimore Sun.

[3][4] While Carver stays in the Western and turns a new leaf after taking Colvin's advice, Herc begins working on the security details for Mayor Clarence Royce.

Marlo's crew realize they are being filmed and give false information (prompting Herc to detain an innocent woman) and then steal the camera.

While attempting to retrieve the camera, Herc interviews Randy Wagstaff, who has knowledge about the murder of Lex, one of Bodie's drug dealers.

Still attempting to retrieve the camera, Herc pulls over Chris Partlow and Snoop, finding a nailgun which ultimately proves to be an important clue for Lester Freamon's investigation into the murders of Lex and Little Kevin.

[6] He attempts to redeem himself by making a note of Stanfield's confidential phone number from Levy's Rolodex and handing it to Carver, who then passes it on to Freamon.

[7] Ultimately, in the fifth-season premiere episode, "More with Less", Herc mentions having come from the Bronx when he makes a reference to his hometown New York Yankees being historically more successful than the Baltimore Orioles.