(CNN) Newly released documents in the Laquan McDonald shooting show how elaborately police appear to have fabricated their version of that moment and how officers stood by each other in verifying the details.

The documents shed new light on just how crucial the release of last month's video was and how it contradicts nearly everything police said happened when veteran police officer Jason Van Dyke shot and killed the 17-year-old McDonald around 10 p.m. on October 20, 2014.

The dashcam video shows McDonald walking down South Pulaski Road with a knife in his hand, but strolling away from officers when Van Dyke jumps out of his vehicle and pulls his gun. Van Dyke began firing six seconds after arriving on scene and took 15 seconds to fire 16 shots.

In those moments, shortly before he is shot, McDonald never faces Van Dyke. He spins after being shot and crumples to the ground, his body stiff as he falls. Van Dyke continues to fire, unloading every round from his 9-mm Smith & Wesson handgun. The teen was struck by all 16 bullets, most of them while he was limp on the ground.

The teen was accused posthumously of aggravated assault of four officers, including Van Dyke. One police record said Van Dyke was "injured by offender" but provided no further detail.

The police records showed dashcam videos were recovered from at least two police vehicles, including Van Dyke's, and "found to be consistent with the accounts of all of the witnesses."

The videos were downloaded for investigators within 24 hours after the shooting.

Recordings from five vehicles were released to the public last month, including the primary dashcam video that shows the shooting, and has led to protests. The city had fought the release for 13 months and only relinquished after a judge ordered its release.

Comparing the officers' accounts of the moment of the shooting with the video reveals stunning differences and what appears to be a conspiracy to create a scenario in which deadly force would be justified.

The video does not capture all of McDonald's encounter with the officers.

Officers had begun pursuing McDonald after getting reports of a young black male attempting to break into vehicles at a parking lot for trucks. According to police reports, a man told McDonald to leave the lot and that the teen swung his knife at him. Police soon spotted McDonald and gave chase. At one point, a request was made for a Taser and additional backup ahead of the fatal shooting.

It is possible that some things the officers describe could have occurred before the time frame captured on video. But their accounts of what happen appear to be describing the moments just before the shooting, which the video covers.

Van Dyke's account of events

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Van Dyke gave this account of what happened.

"McDonald was holding the knife in his right hand, in an underhand grip with the blade pointed forward. He was swinging the knife in an aggressive, exaggerated manner," according to a written account filed by the reporting detective who interviewed Van Dyke.

"Van Dyke ordered McDonald to 'Drop the knife!' multiple times. McDonald ignored Van Dyke's verbal direction to drop the knife and continued to advance toward Van Dyke. When McDonald got to within 10 to 15 feet of Officer Van Dyke, McDonald looked toward Van Dyke.

"McDonald raised the knife across his chest and over his shoulder, pointing the knife at Van Dyke. Van Dyke believed McDonald was attacking Van Dyke with the knife and attempting to kill Van Dyke. In defense of his life, Van Dyke backpedaled and fired his handgun at McDonald to stop the attack."

The video shows Van Dyke took at least one step forward before firing. McDonald lay nearly motionless on the ground as bullets riddled his body.

The report says this: "McDonald fell to the ground but continued to move and continued to grasp the knife, refusing to let go of it. Van Dyke continued to fire his weapon at McDonald, as McDonald was on the ground, as McDonald appeared to be attempting to get up, all the while continuing to point the knife at Van Dyke."

Even after firing 16 shots, the officer said McDonald clutched the knife and refused his orders to put down his knife. Van Dyke's partner approached the teen and kicked the knife from his hand, according to the police records.

The video does show an officer kicking a knife from McDonald's hand while wounded on the ground.

Partner backs up account

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Van Dyke's partner backed up his account, telling the detective that the teen walked down South Pulaski Road, refused officers' orders and then "continued to advance toward the officers."

"When McDonald got to within 12 to 15 feet of the officers, he swung the knife toward the officers in an aggressive manner," Van Dyke's partner said. "Van Dyke opened fire with his handgun and McDonald fell to the ground. Van Dyke continued firing his weapon at McDonald as McDonald continued moving on the ground, attempting to get up while still armed with the knife."

As he waited for an ambulance to arrive on scene, the partner claimed he told the teen: "Hang in there."

Van Dyke's partner told the detective that he didn't fire his gun because Van Dyke was between him and McDonald. But he made it very clear he believed McDonald was "attempting to kill them when the shots were fired."

At least four other officers gave accounts that matched Van Dyke's story, including one who said McDonald "got closer and closer to the officers, continuing to wave the knife."

The video released to the public does not contain any audio.

"Based upon all the facts known at this time and the death of the only offender in this incident," the records said, "this case is now Exceptionally Cleared Closed/Other Exceptional Clearance -- Death of Offender. ...

"The above investigation concluded that Officer Van Dyke's use of deadly force, the discharging of his duty firearm, was within the bounds of Chicago Police Department's use of force guidelines and in conformity with local ordinances and state law."

Reacting to the released documents, Chicago police spokesman Anthony Guglielmi stressed the investigation was handled by the Independent Police Review Authority and not by police. "The Justice Department is currently investigating any actions and statements of CPD officers in connection with this shooting," Guglielmi said in a written statement. "If the criminal investigation concludes that any officer participated in any wrongdoing, we will take swift action."

60-page autopsy

McDonald was pronounced dead at 10:42 p.m. at Mount Sinai Hospital, less than 45 minutes after the shooting began. The 60-page autopsy enumerates the gunshot wounds:

-- "Gunshot wound of the left scalp."

-- "Gunshot wound of the neck."

-- "Gunshot wound of the left chest."

-- "Gunshot wound of the right chest."

It continues, accounting for 16 bullet wounds and ending with "Gunshot wound of the right upper leg." Bullets shredded McDonald's body. Many exited after ripping through muscles and other body tissue.

The police narrative became the public narrative in news reports. But last month, that whole account unraveled after a judge ordered the release of dashcam video of the shooting.

Van Dyke, 37, was charged with first-degree murder in the killing of McDonald hours before the video was released to the public. It marked the first time a Chicago police officer has been charged with first-degree murder for an on-duty fatality in nearly 35 years.

His attorney has maintained Van Dyke feared for his life when he opened fire. The officer was freed on $1.5 million bond on November 30.

Van Dyke is to appear in court at noon (1 p.m. ET) Friday for a continuance hearing that will eventually determine what judge will preside over the high-profile case.

A grand jury this week formally indicted the officer on six counts of first-degree murder and one count of official misconduct. In returning the indictment, the grand jury alleged Van Dyke "without lawful justification, intentionally or knowingly shot and killed Laquan McDonald."

The grand jury did not elaborate as to why six counts of first-degree murder were returned.

Crisis for the Chicago mayor

The shooting has presented Mayor Rahm Emanuel with his biggest crisis yet, with protesters calling for him to resign and a state lawmaker drafting a bill to recall him. He has said he has no plans to step aside and has pledged to reform the Police Department.

But in a sign of the lost trust between the mayor and the community, Emanuel was met at a school event Wednesday with a chant of "16 shots" -- the students showing they stand with the gunned down teen.

An emotional Emanuel last week told a packed City Council chamber that he was "sorry" for the McDonald shooting and that it should never have happened. "I own it," the mayor said . "I take responsibility for what happened because it happened on my watch.

"And if we're going to fix it, I want you to understand that it's my responsibility."

Whether that will be enough to navigate the crisis remains to be seen. A recent poll showed the mayor's approval rating has sunk to a low of 18% and that more than half of Chicago voters believe he should resign.

As of Thursday, nearly 60,000 people from around the nation had signed a petition calling for the mayor and Cook County State's Attorney Anita Alvarez to resign immediately. CREDO Action says more than 2,000 signatures are from Chicago residents.

The police superintendent and the head of the independent board that investigates police shootings resigned amid the fallout from the McDonald video, and the mayor formed a panel to investigate the Police Department and make recommendations for reform. The Justice Department has launched its own investigation, which the mayor said he welcomes.

"We have a mutual goal to create a stronger, better police department that keeps our neighborhoods safe while respecting the civil rights of every Chicagoan," a statement from the mayor's office said.

He expressed a similar sentiment in an opinion piece in the Chicago Tribune earlier this month.

"If any good comes from this tragedy, it should be a historic set of reforms that prevents abuses, promotes transparency and rebuilds the confidence of all Chicagoans that they will be treated fairly," the mayor wrote.

"That is the marker I am setting for myself, the next superintendent and the reform commission I've appointed. And it's one by which I expect to be measured."