At about midnight on December 2, Sean Duffy and his girlfriend, Molly Knudson, were playing MVP Baseball on their PlayStation 2. As on most nights, they sat on the couch in the carpeted living room of their neat Aurora apartment, ripping on each other.

"When I play Home Run Derby, I'm stomping. I get all excited and I'm stomping around. I'm a mess," Duffy says. "It's like I'm 37 going on 3."

And since he was winning, he was doing most of the ripping.

Info Aurora Police Department

Fifteen minutes later, there was a knock on the door. Duffy opened it to find two Aurora police officers, who explained that a downstairs neighbor had complained about the noise. Duffy apologized and joked that he'd been kicking Knudson's ass at PlayStation. It was her day off from her job as a night-shift nurse at the University of Colorado Hospital, and the couple was up late, trying to keep Knudson's regular schedule.

A former emergency medical technician, Duffy met Knudson, 48, when they both worked at Exempla Good Samaritan Medical Center in Lafayette. Since then, he's followed Knudson, who works thirteen-week traveling nursing assignments for a private company in Colorado, Arizona and California.

An hour after the first police visit, Knudson was in the kitchen doing dishes and Duffy was still on the couch, playing the single-player "Home Run Derby" part of MVP Baseball, a part of the game he usually loses. But that night, he says, "I was killing."

He was so excited about his home-run prowess that when he pushed a button on the game controller, he stomped his foot. And when one of his home runs went foul because it hit a pole — a call Duffy still disagrees with — he shouted, "Oh, please!"

According to a police report, however, his downstairs neighbor heard "Police!" and took the yelling and stomping to be retaliation for his having called the cops. So at 1:30 a.m., he called them again. (The neighbor did not return phone calls for this story.)

That's when the trouble started — so much so that Duffy has since filed a complaint against three Aurora Police Department officers involved in the arrest. He claims that these officers, or others, beat him up, leaving him with bruises, a concussion and a sprained neck.

According to the police report, Duffy became combative and violent after letting the police inside his apartment, refusing to sit down, cussing, balling up his fists and yelling at Officer Robert Wong to "let go of him." When Officer Annette Brook tried to help subdue him, Duffy "attempted to grab a hold of my belt," she wrote.

The report goes on to say that Duffy pushed the officers, so they pushed him back against a wall. "I attempted to get my Taser out, but due to our close proximity, I was unable to remove it from my holster," Brook wrote. Duffy was eventually handcuffed.

Duffy says it didn't happen like that at all. After he let the police in, they began ransacking his apartment, flipping pillows off the couch and throwing blankets onto the floor. He says they never identified themselves (though they were wearing uniforms) or told him what they wanted. At one point, Duffy says, he thought maybe they weren't police officers at all, but two people in costumes.

Knudson's first thought was, "We should call the police."

Duffy admits pulling away from Wong but denies being confrontational. "I didn't punch or kick or spit or scratch. I just pushed back and asked him what he was doing. How do you resist when you don't tell me you're placing me under arrest?"

Things got even rougher when more cops showed up. Duffy says an officer grabbed him by the hair and slammed his head into the apartment's metal front door so hard it left a dent. Twice. "Sean's head just bounced like a basketball off the door, and all the color drained from his face," says Knudson, who'd been told to sit on the couch. From there, she took a fifteen-second cell-phone video that shows Duffy being handcuffed and led away, though it doesn't capture any of the alleged assault.

Duffy says two officers roughed him up on the way down the stairs and then threw him head-first into the back of a police car so hard that he hit the door on the other side. Handcuffed and with no way to break his fall, he rolled off the seat and became wedged between it and the floor. He says he lay there for about twenty minutes, listening to the officers laugh and call him a sissy, a pussy and a crybaby.

The police report doesn't mention any of that. It simply says, "When Duffy was taken to a patrol car by officers, he continued to be physically resistant."

Detective Bob Friel, who takes media calls for the Aurora Police Department, says he can't comment on the specifics of the incident because Duffy's complaint against Jerothe, Wong and Brook is still being investigated.

Internal Affairs Section Lieutenant Jeff Turner explains that in general, a supervisor will investigate a complaint against an officer and make a recommendation as to whether it's valid. It's then reviewed by other supervisors, and if it's valid, the officer will be disciplined and, in extreme cases, fired.

The APD received about 200 complaints against its 626 officers last year, Turner says, and of those, 55 were valid on some level. On average, he says, it takes about three weeks for the department to process a complaint.

But police-brutality claims are notoriously tricky to prove, partly because officers often corroborate each others' stories, says Denver lawyer Regina Rodriguez, who last week won a $10,000 settlement for client Trudy Trout, who was shoved to the ground by a Denver cop last year. In that case, a man across the street videotaped the incident, a piece of evidence Rodriguez believes was crucial to proving Trout's claim.

"Generally, people do want to believe what the police say, and the majority of officers are honest, decent people," she says. "Unless you have something that's pretty clear to justify your side, the story will be that you resisted and they needed to use force."

Still, Duffy and his lawyer, Jeffrey Gard of Boulder, are going to try, and they believe they have evidence that will make a good case.

First, there are the photos and videos of Duffy's injuries taken in the days after the alleged assault. Standing shirtless before his bathroom mirror, Duffy zoomed in on the coaster-sized bruise on his right shoulder and the bigger bruise on his left foot. He also filmed the puffy red marks on the side of his head and the welts on his wrists.

Duffy also has an emergency-room report from Boulder Community Hospital, where he went after being released from jail on December 3. It notes his bruises, a sprained neck and a concussion, for which he was prescribed Motrin and Valium.

Then there's Duffy's recent diagnosis for rheumatoid arthritis. His illness has kept him out of work for more than a year while he tries different medications to subdue the pain in his joints, and he recently started taking classes to become a physician's assistant.

Knudson and Duffy have since moved on to San Diego for Knudson's job, but Duffy is due in court on February 17 to face charges of disturbing the peace, resisting arrest and disorderly conduct. Of the three charges, he says he's only guilty of the first.

"They got me there," Duffy admits.

Sometimes, he says, he gets so excited about hitting fantasy baseballs out of the park that he needs a gentle reminder from Knudson to tone it down a bit: "She's like, 'Hey, cowboy, take it easy.'" But he doesn't plan to let his battle with the law spoil his taste for MVP Baseball. "Oh, no," he says. "I played it last night."