Police Chief Thomas Jackson said the officer did not know the teen was a robbery suspect at the time of the shooting and stopped Michael Brown and a companion "because they were walking down the middle of the street blocking traffic."
Darren Wilson, a 28-year-old white officer, has patrolled suburban St. Louis for six years and had no previous complaints filed against him, Jackson said.
Brown's relatives said no robbery would justify shooting the teen after he put his hands up. Family attorneys said Brown's parents were blindsided by the allegations and the release of a surveillance video from the store.
"It appears to be him," attorney Daryl Parks said, referring to the footage, which he said was released without any advance notice from police.
The police chief described Wilson as "a gentle, quiet man" who had been "an excellent officer." He has been on the Ferguson force for four years and served prior to that in the neighboring community of Jennings.
Wilson, who was placed on administrative leave after the Aug. 9 shooting, "never intended for any of this to happen," Jackson said.
According to police reports released Friday, authorities received a 911 call at 11:51 a.m. on the day of the shooting reporting a robbery at the Ferguson Market. An unidentified officer was dispatched to the store, arriving within three minutes. The officer interviewed an employee and customer, who gave a description of a man who stole the cigars and walked off with another man toward a QuikTrip store.
Descriptions of the suspect were broadcast over the police radio. The officer did not find the suspects either on the street or at the QuikTrip, the reports said.
The robber took a box of Swisher Sweets, a brand of small, inexpensive cigars. The suspects were identified as 18-year-old Michael Brown and 22-year-old Dorian Johnson, according to the reports.
Separately, Wilson had been responding to a nearby call involving a sick 2-month child from 11:48 am until noon, when he left that place. A minute later, he encountered Brown walking down Canfield Drive. The documents contained no description of what happened between Brown and Wilson.
Johnson has told reporters that the officer ordered the pair to move onto the sidewalk, then grabbed his friend's neck and tried to pull him into the car before brandishing his weapon and firing. He said Brown started to run and the officer pursued him, firing multiple times.
Another family attorney, Benjamin Crump, noted that police did not release a photo of the officer but released images from the security video that they say show Brown grabbing a man inside the store. Crump said he had not seen the photos.
Police "are choosing to disseminate information that is very strategic to try to help them justify the execution-style" killing, said Crump, who also represented the family of Trayvon Martin, the teenager fatally shot by a Florida neighborhood watch organizer who was later acquitted of murder.
The Aug. 9 video appears to show a man wearing a ball cap, shorts and white T-shirt grabbing a much shorter man by his shirt near the store's door. A police report alleges that Brown grabbed the man who had come from behind the store counter and "forcefully pushed him back" into a display rack.
Police found evidence of the stolen merchandise on Brown's body. Authorities determined that Johnson was not involved in the robbery and will not seek charges against him, Jackson said.
Brown's uncle, Bernard Ewing, said the shooting was unnecessary, even if his nephew was a robbery suspect.
A robbery "still doesn't justify shooting him when he puts his hands up," he added. "You still don't shoot him in the face."
Brown's death ignited four days of clashes with furious protesters. The tension eased Thursday after the governor turned oversight of the protests over to the Missouri Highway Patrol. Gone were the police in riot gear and armored vehicles, replaced by the new patrol commander who personally walked through the streets with demonstrators.
On Friday night, the Rev. Jesse Jackson linked arms with protesters as they marched to the site where Brown was killed. Jackson bent over in front of a memorial cross and candle and sighed deeply. He urged people to "turn pain into power" and to "fight back, but not self-destruct" through violence.
The scene was eclectic Friday night as hundreds gathered for a sixth straight evening. A man on a bullhorn called for a revolution. A young man waved a Bible while citing scripture. Some took selfies in front of a convenience store that had been burned by looters Sunday. Boys tossed a football, and horns and loud music blared.
To Vida Weekly, 51, it was still a somber occasion. She walked through the crowd holding high a sign that read: "The police killed Michael Brown and now they are trying to kill his character."
Police have said Brown was shot after an officer encountered him and another man on the street during a routine patrol. They say one of the men pushed the officer into his squad car, then physically assaulted him in the vehicle and struggled with the officer over the officer's weapon. At least one shot was fired inside the car before the struggle spilled onto the street.