A man suspected of assault was shot on a north Minneapolis street by a police officer early Sunday while allegedly hindering emergency responders from aiding his victim.

The shooting ignited a chaotic scene of shouting and taunting bystanders who believed the man was handcuffed before police opened fire.

Police Chief Janeé Harteau said Sunday afternoon that her department's preliminary information is that the man was not handcuffed when police shot him.

Police did not identify the man, but Nekima Levy-Pounds, president of the Minneapolis NAACP, said in a statement that he was Jamar Clark, a black man in his mid-20s, and that he had been "shot and killed" by police.

The debate on the public stage is showing no signs of easing. The Minneapolis chapter of Black Lives Matter has scheduled a news conference for 9 a.m. Monday outside the Police Department precinct headquarters on the North Side. The chapter is calling for the release of any video police might have of the shooting as well as disclosure of the names of the officers involved.

Clark's relatives, including several sisters, gathered in a room on the seventh floor intensive-care unit at Hennepin County Medical Center Sunday afternoon where a physician told them that Clark is brain dead, according to one family member. Clark was shot "in the head, execution style," a family member said.

A hospital chaplain and a member of the Bureau of Criminal Apprehension visited the family in a consultation room where they spent most of Sunday afternoon awaiting news about Clark.

Ambulance was called

The confrontation began about 12:45 a.m. in the 1600 block of Plymouth Avenue N., according to police. Authorities have yet to reveal the identities of the people involved or elaborate on the exact circumstances leading up to the assault.

Nekelia Sharp, who lives across the street, said an ambulance was called after the suspect and his girlfriend got into an argument. While paramedics were taking the girlfriend away, the suspect tried to talk to her. Sharp said that's when he was handcuffed and then shot.

Bystanders swarmed as emergency vehicles were responding. In a video posted on Facebook by a witness, one woman was repeatedly shouting, "Y'all just killed that man!" Others nearby were pointing at police and taunting them.

A few seconds of the video showed an emergency responder kneeling over someone on the ground.

Witnesses said that officers pushed the increasingly agitated crowd back toward the Elks Lodge across the street and that several people were pepper-sprayed.

"We've been saying for a long time that Minneapolis was one bullet away from Ferguson. Well, that bullet was fired last night," said Jason Sole, an associate professor at Metropolitan State University and a member of the local NAACP chapter.

The NAACP statement quoted witness Teto Wilson, who said Clark "was just laying there. He was not resisting arrest. Two officers were surrounding the victim on the ground, an officer maneuvered his body around to shield Jamar's body, and I heard the shot go off."

According to police scanner audio of the incident, posted on the MN Police Clips Facebook page, the apparent domestic confrontation started in an apartment. An officer is later heard requesting all available squad cars, saying, "We've got a big crowd; we need a lot of cops."

At City Hall

The incident has been turned over to the state BCA for investigation, said Harteau, who added that two officers were placed on standard administrative leave.

"Please contact the BCA," the chief said during a midday City Hall news conference with Mayor Betsy Hodges and BCA Superintendent Drew Evans at her side. "We need to know the truth."

She also cautioned everyone that "there is a lot of speculation out there" about how the incident unfolded.

Evans said there were "handcuffs at the scene," but that the preliminary information is that the man was not cuffed. Looking into that aspect of the case "is part of the active investigation," Evans said. "These investigations take time, and we want to make sure we are thorough."

Officers answered a call about an assault and were then alerted that the suspect "had returned to the area and was confronting paramedics and disrupting their ability to render aid," a statement from police read.

As officers were attempting to calm the suspect, an altercation erupted with the man, "who was not in handcuffs," the statement continued.

"At some point during the struggle, an officer discharged his weapon, striking the suspect," the statement read.

Anger, lack of trust

Anger and distrust fueled a rally called by Black Lives Matter Minneapolis that began at 3 p.m. at the shooting scene and continued into the evening a few blocks away outside the police department's Fourth Precinct headquarters.

The protest began with about 250 people ringing the block where Clark was shot, to create a "no-cops zone." Its leaders refused to participate in a community listening session called by Hodges at the Minneapolis Urban League, also on Plymouth Avenue N.

Rally speakers held firm to the view that Clark was handcuffed when shot and voiced doubt that a BCA probe could be impartial.

Inside the Urban League, Hodges and Harteau stepped back after introductory comments about the call for independent review, as the gathering gave way to shouts between community members in the room.

The meeting fell apart a short time later after people were drowned out by yells of "Justice for who? Jamar!"

Hodges managed to squeeze in a short reply to a question about whether a BCA investigation could be trusted, saying that the agency had been "looking at these kinds of cases for a long time."

Later, a smaller crowd continued to demonstrate outside the Fourth Precinct station, where a Black Lives Matter banner was hung and food and blankets were brought in.

Mica Grimm, an organizer with Black Lives Matter Minneapolis, was among about 10 college students and activists occupying an entryway at the station.

She said people plan to stay there — taking turns for weeks, if necessary — until the officer responsible for the shooting is arrested or indicted.

"We're here because police officers have gotten away with murder for so long and we're tired of it," Grimm said.

Protesters and city and police officials agreed on one thing: Anyone who witnessed or has a cellphone video of the shooting should step forward. Witnesses are urged to call the BCA at 651-793-7000, the mayor told the Urban League crowd.

Star Tribune staff writers Anthony Lonetree and Karen Zamora contributed to this report. Paul Walsh • 612-673-4482