At issue is an arrest of two men outside a nightclub last year that was caught on police video. It shows 25-year-old Shawn Johnson on the ground being arrested by police when his friend, 24-year-old Michael DeHererra called his father, a sheriff's deputy, for help. Another officer then grabbed DeHerrera, slammed him to the ground and repeatedly beat him with a metal club.
Michael's father, Anthony DeHerrera, said he could hear the altercation for seven minutes through the phone's open line.
"The last thing I heard is, 'We have to get rid of the phone, they're recording us.' And then the phone went dead," he said.
He said both he and his wife heard the incident.
"Michael was screaming on the phone, 'Dad, they're beating up Shawn!'" the elder DeHerrera said. "Then all of a sudden I hear some sirens in the background, so I figure some kind of law enforcement is there, wherever he's at, they're going to get him help. Then the next thing I hear is, drop the phone, some obscenities, and then I hear a thud. And then Michael wasn't talking anymore, so I knew he had been hit."
Johnson told "The Early Show" that at no point in the altercation did he fight back.
"I remember when I woke up in the street, I was already in handcuffs. There were two officers on top of me and somebody was grinding into my ankle. There was no way for me to fight back," Johnson told "Early Show" co-anchor Harry Smith. "I remember even yelling, 'Someone call the police, can someone call the police?'"
An independent office that monitors Denver police released a report Monday saying two officers should have been fired for trying to cover up allegations of excessive force during the arrests.
Independent monitor Richard Rosenthal said he believes the police video of the April 2009 incident clearly shows one officer doctored his account to keep the second officer from getting in trouble.
The video shows an officer grabbing one of the men and forcing him down. The camera moves back, but a person in the corner of the frame can be seen repeatedly striking something.
However, the FBI spokesman Dave Joly won't say whether their involvement will lead to an official investigation.
Denver Manager of Safety Ron Perea said that while inflammatory, the video doesn't tell the whole story. He stands behind his decision on disciplining the officers rather than firing them as Rosenthal recommended.
Mayor John Hickenlooper has said Perea and Rosenthal both did their jobs, but added that when viewed in isolation, the video "does not reflect well on the officers involved."
A police union official called Hickenlooper's request for a review by the FBI "political grandstanding."
"The officers had due process. It's over. It's done," Vince Gavito, vice president of the Denver Police Protective Association, told KUSA-TV in Denver.
Hickenlooper said he is just trying to make sure the city acts deliberately and carefully.
Joly said the FBI is sometimes asked to review local police when officers are accused of violating people's civil rights, including allegations of excessive force. If the bureau finds violations, he said it can recommend that the U.S. attorney file federal charges against police.