Daniel Hersl, the notorious Baltimore police officer who went to federal prison as part of the Gun Trace Task Force corruption scandal, has died. He was 55.

Hersl was released early in January, after serving about eight years of his 18-year prison sentence, due to cancer. His probation officer on Thursday notified the judge overseeing his supervised release that Hersl had died Oct. 5 in Kingsville. His attorney did not respond to requests for comment.

Hersl was among six officers indicted on racketeering charges in 2017 following an FBI wiretap investigation that found what police brass considered to be an elite plainclothes unit was stealing drugs and cash, lying about arrests and collecting overtime pay they didn’t earn.

Some of the officers charged had flown under the radar prior to their arrests — but not Hersl.

For years, his name rang out in the streets as a brutal officer who was on the take. A judge once remarked on dozens of internal complaints he had racked up, and The Baltimore Sun featured him in a series about officers who had been the subject of multiple lawsuits in which the city paid out settlements. The rapper Young Moose name-checked him in not one but two of his songs before Hersl’s arrest on federal charges.

Still, after being charged and seeing other officers flip and testify against him, Hersl vehemently denied the accusations for years. He once compared himself to the famed New York City undercover detective-turned-whistleblower Frank Serpico, claiming he was a good cop working among the bad.

As his attempts to win freedom were denied, Hersl relented and apologized for his conduct.

“With my health on my mind, I want to seek peace with my actions and ask for forgiveness from the people of Baltimore, victims of the GTTF and everyone affected,” he wrote, concluding: “I truly offer my sincere apologies to everyone.”

Hersl, who grew up in the Highlandtown area of Baltimore, was one of six children. He lost his father when he was 7. He joined the Baltimore Police Department in 1999.

He was recognized with the department’s highest award, the Medal of Honor, for saving a partner in a shootout in 2012.

He was portrayed in the 2023 HBO series “We Own This City” by Baltimore actor Josh Charles.

In 2020, the writer D. Watkins wrote an essay about his run-ins with Hersl when Watkins was selling drugs and Hersl reigned over East Baltimore — and how both were caught up in larger systems.

“It’s not at all remarkable that Hersl didn’t change, because he never had to be held accountable. America didn’t give me any tools to change, and it didn’t give Daniel Hersl any reason to change,” Watkins wrote. “But instead of addressing these problems, it treats us both as exceptions, rewarding me and locking him away, so that it can forget about these particular East Baltimore boys and let the game go on.”