Marcus Worthy says he was handcuffed and obeying commands when he was struck in the head by Buffalo Police Officer Corey Krug.
Krug's fellow officers say Worthy was resisting and that Krug was simply reacting to the discovery of a gun in Worthy's pocket.
The he-said, she-said nature of Krug's federal court trial continued this week as prosecutors sought to introduce evidence of another alleged instance of police brutality by the officer.
An 18-year veteran of the force, Krug is accused of using excessive force in three separate incidents dating back more than eight years.
"I did exactly what they asked me to do," Worthy told the jury. "I put my hands up."
Why, asked Assistant U.S. Attorney Aaron J. Mango.
"Because I didn't want them to shoot me," he answered.
In sharp contrast, the first police officer on the scene that night in 2010 said Worthy refused to put his hands up and, at one point, she could see only one of them.
"I believed him to have a gun in his hand," said Lt. Melinda Jones.
Jones, who testified that she was in the police academy with Krug, said Worthy wanted to know why he should put up his hands. She also said that, at one point, one of the officers discovered a gun on Worthy.
"I remember hearing someone yell, 'gun,' " she told U.S. District Judge Richard J. Arcara.
There was a gun, but Worthy had a pistol permit to carry it.
Worthy insists he was compliant that night on Langmeyer Street and that Krug and the other officers overreacted to the report of an armed man at the scene.
"He just kept swinging at me," Worthy said of Krug.
Worthy said he was hit with a flashlight and was later taken to Erie County Medical Center where he received four staples in his head.
In the 911 call that led to the incident, the caller said an armed black man wearing blue pants and a white T-shirt was threatening a woman on Langmeyer.
Det. Thomas Herbert, one of the first officers to arrive after Jones, said the 911 dispatch was a "Priority One" call indicating the suspect had a gun. He also claims officers at the scene repeatedly asked Worthy if he was armed.
"He kept saying, 'no,' " Herbert said.
An eyewitness to the incident said she was on her front porch and could hear officers asking Worthy about a gun before one of them struck him repeatedly on the head with a long black object.
Crystal Harris, the mother of a woman who was with Worthy that night, said he immediately succumbed and looked limp like a "rag doll." She also claims officers laughed at Worthy once he was down.
On cross-examination, defense attorney Nicholas A. Romano suggested Harris' version of what happened that night has changed more than once over the years.
"I can't recall anything but the beating," she told Romano. "That incident will never leave me. That incident will never leave my mind."
Herbert, the officer who found the gun that night, said he and two others officers were struggling with Worthy when he felt the gun in a holster on Worthy's right hip.
He also testified that Krug admitted striking Worthy in an effort to subdue him.
"Did you see him beat like a rag doll?" asked defense lawyer Herbert L. Greenman.
"No," said Herbert.
Worthy, who was 27 at the time, is suing Krug, Jones, Herbert and every other officer at the scene that night as part of a civil suit that also names the City of Buffalo. The suit is still pending.
Krug, who is currently suspended with pay, is also accused of using excessive force against two other men in 2011 and 2014.
The trial resumes Friday.