GRAND RAPIDS, Mich. (WOOD) — A man is suing a Grand Rapids police officer and an FBI agent, claiming he was brutally beaten by them when they were undercover looking for a different man.

In the federal lawsuit filed Monday, 23-year-old James King argues excessive force was used and his constitutional protections against unreasonable search and seizure were violated when he was arrested in July 2014.

The arrest happened near the corner of Leonard Street NW and Tamarack Avenue in Grand Rapids. According to court documents, King says he was walking to work at The Geek Group when the officer and agent in plainclothes approached him, claiming they were police and asking for his identification because he matched a rough description of a home invasion suspect.

King complied at first, according to the lawsuit, but when the officers removed his wallet and said he was under arrest, he started running because he thought he was being robbed. The lawsuit alleges he made it only a few steps before he was tackled and then choked until he lost consciousness.

A witness captured video on a cellphone of a handcuffed King lying face-down in the grass after the struggle was over. In the video, witnesses can be heard recounting what happened:

“They were literally pounding him in the head, though,” one witness said. “They were pounding his head for no reason.”

King was arrested for assaulting the undercover officers and resisting arrest. He spent the weekend in jail before posting bond and being released, according to the lawsuit.

Pictures taken after the incident show him with a dark bruise under his left eye and both eyes red because of burst blood vessels.

In the lawsuit, he claims he had to drop out of college because of the incident.

“James learned the hard lesson that unless you’re 6 years old, white and lost, the police aren’t necessarily your friends and he got beat down for it,” Chris Boden, the president of The Geek Group, said.

He said he’s furious about what happened.

“This is real and I watched a kid’s life get destroyed for it,” he said. “I’m pissed as hell.”

Other witnesses who have come forward painted a different picture. One witness said he helped police subdue King, who he said bit an officer’s arm.

“When they tackled him, they proceeded to yell, ‘Help us, help us.’ And they were yelling that they were detectives. So I sat and watched for two seconds, (then) I ran across the street helped hold him down, pretty much,” the witness, who didn’t want to be identified, told 24 Hour News 8.

Another anonymous witnesses also said the officers’ actions were justified:

“At not one point did I see him knocked unconscious and laying still. He was flailing at all times,” the witness said.

Both witnesses claim police were clearly wearing badges around their necks.

Police later realized King was not the home invasion suspect they were looking for. He was tried on the assault charges, but ultimately acquitted.

Several witnesses told 24 Hour News 8 that another officer who arrived on scene after the incident was asking people to delete any cellphone video to protect the officers’ identities.That third officer is also named as a defendant in the lawsuit.

The City of Grand Rapids declined comment Tuesday.