(CNN) The United Airlines passenger who was left bloodied and bruised after being forcibly removed from a flight earlier this month was swinging his arms, his hands balled into fists, as officers from the Chicago Department of Aviation tried to pull him out of his seat, according to incident reports from the officers involved.

Officer Mauricio Rodriguez, the first officer who responded to the April 9 incident, largely confirmed accounts by other passengers about how David Dao was taken off the plane, but said that when fellow officers tried to remove Dao, he "started swinging his arms up and down violently," according to his report.

Officer James Long gave a similar account.

"The subject started swinging his arms up and down with a closed fist," Long said in his report.

The incident began when gate agents asked for volunteers to give up their seats on Louisville, Kentucky-bound Flight 3411 to make room for a United crew that needed to meet another flight. Dao, 69, and his wife initially agreed to take a later flight, a fellow passenger told CNN, but then changed their minds when they learned the next flight wouldn't depart until the following day.

"He was very emphatic: 'I can't be late. I'm a doctor. I've got to be there tomorrow,'" Jayse Anspach recalled.

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The airline offered compensation to anyone willing to give up their seats, but when not enough people volunteered to go, Dao was apparently chosen at random.

In video shot by Joya and Forest Cummings, who were sitting behind him, Dao repeatedly refuses to disembark, explaining to officers that he is a physician and must work in the morning.

The Cummingses told CNN in a phone interview three days after the incident that Dao was not belligerent and got only mildly upset when a second officer arrived, demanding he leave the plane, they said. Dao never raised his voice, the couple said.

The officers' reports -- obtained through a Freedom of Information Act request by the watchdog group Judicial Watch -- paint a different picture. The officers' reports said they were called to the plane in Chicago's O'Hare International Airport because of a passenger "yelling about leaving the aircraft."

"I'm not getting off," Dao told officers in an aggressive manner, according to Rodriguez's report. "I'm not leaving this flight that I paid money for. I don't care if I get arrested."

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It was as officers began to pry Dao from his seat that he started screaming, witnesses said. Disturbing images of the incident soon hit the Internet, showing Dao -- with blood trickling from his mouth -- being dragged down the aisle of the plane by his wrists, limp and dazed, with his glasses askew on his face and his shirt riding up his torso, stomach exposed.

'Flailing and fighting'

When officers physically lifted Dao from his seat, Rodriguez's report said, Dao's flailing caused Long to lose his grip on Dao, and the passenger fell forward and hit his mouth on the opposite seat's armrest.

Long's statement described Dao as "flailing and fighting" as officers tried to remove him from his seat.

Long, who finally removed Dao from the plane, also recounted that Dao was then placed on the floor of the jetway and was offered water after saying that he was a diabetic. Then, Long's report says, Dao pushed past Rodriguez and another officer and ran back into the plane.

"I'm not getting off the plane, just kill me. I want to go home," Dao said, holding onto a pole in the galley area of the aircraft, according to Rodriguez's report.

A crew member, whose name is redacted from the documents, confirms the reports, writing that Dao "was spitting blood saying, 'I'm going home. Just kill me.'"

Rodriguez's statement to his watch commander, along with another officer's statement which CNN has seen, was submitted "under duress," according to the report. "I am only giving this statement at this time because I know that I could lose my job if I refuse the direct order given to me," the statement reads.

The four officers named in the report -- Rodriguez, Long, Steve Smith and John T. Moore -- were all placed on leave within 10 days of the incident, documents show.

The Chicago Department of Aviation said at the time that the incident "was not in accordance with our standard operating procedure, and the actions of the aviation security officer are obviously not condoned by the Department," referring to Long.

CNN has attempted to reach representatives for the officers named in the report, but did not receive responses immediately.

In a statement to CNN affiliate WLS, a union representing police in Chicago said the investigation into the incident by the union and the Chicago Department of Aviation is still under way.

"We will reserve further comment about this particular incident until the investigation by both parties is completed," the Local 73 said.

Dao's attorney, Thomas Demetrio, said in a statement issued by his law office that the reports were "utter nonsense. Consider the source."

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Belated contrition

United Airlines CEO Oscar Munoz initially said Dao was belligerent, leaving security officers no choice but to employ force in removing him.

Munoz later struck a tone of contrition, telling ABC's "Good Morning America" that he felt "ashamed" over the incident and vowed never again to let law enforcement remove "a booked, paid, seated passenger" from a plane.

Munoz has pledged a full review of the incident by April 30 "to fix what's broken so this never happens again."

United took a hit on the stock market, with its shares slipping by 4% in the wake of the incident. Initially the company's market value plummeted by $1 billion

Lawsuit in the works

Dao suffered a concussion, a broken nose and lost his two front teeth, his attorney told reporters shortly after the incident, adding that the 69-year-old physician will file a lawsuit.

"If you're going to eject a passenger, under no circumstances can it be done with unreasonable force or violence. That's the law," Demetrio said. "For a long time, airlines -- United, in particular -- have bullied us. ... We want respect and we want dignity. That's it. Not a big deal."

The lawsuit will be filed in Cook County Circuit Court in Illinois, Demetrio said, indicating it would target both the airline and the city of Chicago.