About 150 people Sunday marched from the Western Beef Supermarket in Mineola to Garden City police headquarters, where they protested the alleged police beating of a retired Nassau County correction officer.

Ronald Lanier, who is African-American, said he was shopping Wednesday at the Western Beef when two white police officers mistook him for a shoplifting suspect, approached him from behind, threw him to the ground and handcuffed him before beating him. Lanier has said he was treated for bruises at Winthrop-University Hospital in Mineola.

Lanier, 53, said Sunday that Garden City police should discipline the officers for their actions, and that promises of retraining officers was not enough.

“What I want out of this is for the officers to be held accountable for their actions,” Lanier said. “I’m tired of the department . . . stating when an officer does something wrong . . . ‘We need to retrain the officers.’ It’s not about retraining, it’s about making them be held accountable for their actions.”

Lanier’s family was present to support him during the demonstration, before which protesters marched about 1 1⁄2 miles, and several said events have been devastating.

“He [Ronald Lanier] is really struggling right now,” said his sister, Denise Lanier, of Baldwin. “It feels like a flashback to Jim Crow laws. Who are you going to scream to when the person that you scream to does not protect you?”

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Lanier’s attorney, Frederick K. Brewington, of Hempstead, said the officers involved should be fired.

“They never talked to him [Lanier] to make sure he was the right person,” Brewington said. “The abuse he suffered at their hands — it was like they were beating an animal. We want them to not be disciplined, we want them to be completely taken out of police work. They need to lose their jobs.”

In regards to the allegations made by Lanier, Garden City police Lt. Joseph Lennon said Monday: “It is under investigation and when that investigation is complete we will release that information.”

Garden City Mayor Nicholas P. Episcopia, on the advice of the village attorney, has declined to comment on any potential litigation.

Brewington also called for state Attorney General Eric T. Schneiderman to investigate the Garden City Police Department. Calls and emails to Schneiderman’s office late Sunday were not immediately returned.

Lanier said he identified himself as a fellow law enforcement officer during the incident, but that did nothing to stop the beating.

“I told them and they let it fall on deaf ears,” he said. “It was trauma, I was shocked. And all that came across my mind was [shooting victim] Sean Bell and the other people . . . that didn’t have a chance . . . I had all these credentials, and it didn’t even matter.”

Lanier, who served in the Army and volunteered at Ground Zero after 9/11, has notified the Garden City Police Department and Garden City Village that he intends to sue.

Brewington said he had already filed a notice of a claim on Lanier’s behalf.

With Joye Brown