CHICAGO -- Three seconds. On a dashcam video clock, that's the amount of time between the moment when two officers have their guns drawn and the point when Laquan McDonald falls to the ground.
The video, released to the public for the first time late Tuesday, is a key piece of evidence in a case that's sparked protests in Chicago and has landed an officer behind bars.
The 17-year-old McDonald was shot 16 times on that day the video shows in October 2014. Chicago police Officer Jason Van Dyke was charged Tuesday with first-degree murder.
The nearly seven-minute video shows the dashcam view as a patrol car approaches the scene.
There is no audio in the video, so it's unclear what's being said. But about five minutes and 20 seconds in, McDonald is seeing running, then walking down a road toward several squad cars with flashing lights.
With his left hand near his pocket, McDonald veers away from two police officers, who have their guns drawn.
Seconds later, McDonald appears to spin around, then falls, writhing as shots keep hitting his body, sending puffs of smoke into the air.
An officer approaches McDonald and appears to kick an object out of his hand.
The remaining minute of the video shows several officers walking near McDonald. They do not approach his body or render aid.
Prosecutor points to video
**Editor's note: The above video is the unedited dashcam from Chicago police, and it is graphic, viewer discretion is advised**
Prosecutors point to the dashcam video in their description of what happened the day of the shooting.
The circumstances leading to the shooting began at 9:47 p.m. on October 20, 2014, according to a court document filed by prosecutors Tuesday. It started when a dispatcher told officers that a citizen was holding a man (later identified as McDonald) caught breaking into trucks and stealing radios in a parking lot.
Two officers had guns drawn as McDonald jogged by, knife in his right hand. Van Dyke, who was about 10 feet away, stepped toward him and opened fire at about 9:57 p.m, the document says.
"An analysis of the video establishes that 14 to 15 seconds passed from the time defendant fired his first shot to clear visual evidence of a final shot," the court document says.
Less than 20 seconds after the shooting starts, the court document says, an officer approached McDonald and kicked a knife with a three-inch blade out of his hand.
According to the document, there's one thing the video "clearly does not show": McDonald advancing toward the officer.
Why was video released?
After a journalist filed a freedom of information request, a judge ruled that police had to release the video by November 25.
Police said they hadn't released the video sooner because it had been evidence in an active criminal investigation.
"We did not want to do anything that might interfere with the ongoing investigation," the statement said. "For example, releasing a video during a pending investigation has the potential to compromise eyewitness testimony because witnesses may adjust their testimony to fit what they or others perceive in the video."
Officials brace for protests
As she announced the charges against the officer, Cook County State Attorney Anita Alvarez said she moved up the timing of her announcement because of the video's impending release.
"I do not want the public to view this video without knowing this very important context that with these charges we are bringing a full measure of justice that this demands," Alvarez said.
Daniel Herbert, an attorney representing the officer, told reporters that the case should be tried in court, not in the media or on the streets.
"People viewing this videotape will have the brilliance and benefit of hindsight 20/20 vision," Herbert said.
"This is not a murder case, despite what you heard in the courtroom. It's truly not a murder case, and we feel that we will be very successful in defending this case," the attorney said.
As they prepared to release the video, Chicago officials said they were bracing for protests.
"I understand that the people will be upset and will want to protest when they see this video," Mayor Rahm Emanuel said. "We as a city must rise to this moment."