CHICAGO (AP) — Police officers who watched a colleague shoot a black Chicago teenager 16 times filed reports depicting a very different version of events than what dashcam footage showed, portraying the teen as far more menacing than he appeared in the video.

The city released hundreds of pages of documents late Friday pertaining to the October 2014 killing of 17-year-old Laquan McDonald by Jason Van Dyke, a white police officer. Van Dyke was charged with first-degree murder last month, only hours before the department released the video under a court order, sparking protests and accusations of a cover-up.

The video, which the city kept from the public for more than a year, shows McDonald veering away from officers on a four-lane street when Van Dyke, seconds after exiting his squad car, opens fire from close range. The officer continues shooting after McDonald crumples to the ground and is barely moving. The video does not include sound, which authorities have not explained.

In the newly released police reports, several officers including Van Dyke and his partner described McDonald as aggressively approaching officers while armed with a knife. At least three other officers, including his partner, supported key details in Van Dyke's portrayal of events.

The officers' version, recorded in more than 300 pages of handwritten and typed reports, prompted police supervisors to rule at the time that McDonald's death was a justifiable homicide and within the use of force guidelines, even though the dashcam video also was available to them shortly after the shooting.

Van Dyke told an investigator McDonald was "swinging the knife in an aggressive, exaggerated manner" and "raised the knife across the chest" and pointed it at Van Dyke, according to one report. Multiple officers reported that even after McDonald was down, he kept trying to rise while holding the knife.

"In defense of his life, Van Dyke backpedaled and fired his handgun at McDonald, to stop the attack," one report reads. "McDonald fell to the ground but continued to move and continued to grasp the knife, refusing to let go of it."

Van Dyke told an investigator he feared McDonald would rush him with the knife or launch it at him. He also noted a 2012 Chicago Police Department warning about a knife capable of firing a bullet, according to the reports. The reports included a copy of the warning issued by an unidentified "Midwest intelligence organization" that was circulated to officers.

The reports add to questions about the department's handling of the shooting. The U.S. attorney's office is investigating, and several officials have called for the U.S. Justice Department's civil rights division to open a wider investigation of police practices, similar to ones conducted in Ferguson, Missouri, and elsewhere.

The shooting happened while protests were still roiling Ferguson months after the fatal police shooting of an unarmed black 18-year-old, Michael Brown. His death revived questions about police treatment of minorities throughout the United States and energized the national Black Lives Matter movement.

Chicago officials fought in court for months to keep the McDonald video from being released. The city's early efforts coincided with Mayor Rahm Emanuel's re-election campaign, when he was seeking African-American votes.

Emanuel has said he didn't see the video until it was released publicly. He and a number of aldermen have said they relied on the city attorney, who did view it, when they signed off on a $5 million settlement with McDonald's family even before the family filed a lawsuit.

In an op-ed article, Emanuel denied a cover-up and said he "strongly" rejects any alleged connection to his re-election campaign. He said the city was following a longstanding practice of releasing such material only after an investigation was complete.

Emanuel fired Chicago Police Supt. Garry McCarthy on Tuesday.

Van Dyke's attorney, Dan Herbert, maintains the video doesn't tell the whole story, and says the officer feared for his life and acted lawfully. Herbert didn't immediately respond to requests for comment.

What's on video and what the officers reported could all be true, said Dean Angelo, president of the Chicago police officer's union, because each officer had "a different perspective," which could vary significantly from the fixed car camera.

It's unclear whether the newly released documents could lead to more officers being prosecuted. The officers would have Fifth Amendment protection for anything they said during an internal investigation, but their initial police reports could be used in an obstruction of justice case against them, said Phil Turner, a former federal prosecutor in Chicago.

"You've got police reports that say the guy lunged and a video that says that didn't happen at all," Turner said.

Chicago police spokesman Anthony Guglielmi said the city's Independent Police Review Authority, not the police department, conducts investigations of officer-involved shootings and the agency was given all evidence from the scene. The authority has not released its report on McDonald's death.

"If the criminal investigation concludes that any officer participated in any wrongdoing, we will take swift action," Guglielmi said.

The Rev. Jesse Jackson said the documents show police "misrepresenting" what happened and called for an escalation of protests Sunday in the city's business district.

Requests for comment to representatives for Emanuel, Cook County State's Attorney Anita Alvarez and the police review authority weren't immediately returned.

McDonald was being chased by police after reports he was burglarizing vehicles.

The police reports refer to him as the "offender" and Van Dyke and other officers as "victims."

Van Dyke's partner, identified as Joseph Walsh, told an investigator that he repeatedly yelled "Drop the knife!" at McDonald and backed up as the teenager "continued to advance toward the officers." He said McDonald "swung the knife toward the officers in an aggressive manner" before Van Dyke shot him and that he believed McDonald was "attempting to kill them."

Walsh said McDonald attempted to get up after falling, "while still armed with the knife." He said he eventually kicked the knife away from McDonald and then told the dying teenager "Hang in there" as an ambulance was called.

When announcing charges against Van Dyke, Alvarez said McDonald's knife, which had a 3-inch blade, was folded when recovered from the scene. One of the police reports said the knife's blade was open.

One report said McDonald showed "irrational behavior," such as ignoring verbal directions, "growling" and making noises. A medical examiner's report said the hallucinogen PCP was found in his system.

Redactions in the police reports cover signatures, a reporter's cellphone number, the serial number of the officer's gun and McDonald's address.

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Associated Press writers Michael Tarm and Don Babwin contributed to this report.