Michael Brown shooting: Chaos erupts on the streets of Ferguson after autopsy shows teenager was shot six times – twice in the head

St Louis County Police Department tweeted reports that Molotov cocktails were being thrown at officers

Chaos erupted on the streets of Ferguson, Missouri again last night as police unexpectedly fired tear gas into a crowd of demonstrators, including children and members of the media, almost two hours before the start of an official curfew.

The renewed violence began as a private autopsy report was released showing that Michael Brown, the unarmed black teenager killed by a white police officer in the St Louis suburb last weekend, had been shot six times – twice in the head.

The fresh dissidence has led to Jay Nixon, the Governor of the state of Missouri, ordering the deployment of National Guard troops to “protect life and property”, he said in a statement this morning.

The military will, he says, will “maintain peace and order” by closing streets and thoroughfares, if it must, after the events that have unfolded have “continued to create conditions of distress and hazard to the safety, welfare and property of the citizens of the community beyond the capacities of local jurisdiction”.

In the midst of what appeared to be a peaceful protest last night, the St Louis County Police Department tweeted reports that Molotov cocktails were being thrown at officers, and that shots had been fired in the area. Police launched smoke canisters and tear gas into the crowds, which sent hundreds fleeing, with many reportedly covering their faces to escape the gas.

Earlier yesterday, it seemed tensions might finally have been quelled in Ferguson, where police and protesters have clashed almost nightly since Mr Brown’s death on 9 August. Captain Ron Johnson of the Missouri State Highway Patrol, the black officer who has become the public face of the law enforcement response, received a standing ovation when he addressed the Brown family and other community members on Sunday at the town’s Greater Grace Church.

People make their way through the haze as tears gas fills the street during a demonstration over the fatal shooting of teenager Michael Brown by a police officer in Ferguson, Missouri (Getty Images)

Capt. Johnson reminded the crowd that he, too, was from Ferguson, and that he had much in common with many families there, including a son whom he said wears baggy trousers and sports tattoos. “We all ought to be thanking the Browns for Michael, because Michael's going to make it better for our sons, so they can be better black men,” he said.

Missouri Governor Jay Nixon last week asked the Highway Patrol to take over responsibility for security in Ferguson, after four nights in which local police had met largely peaceful protests with riot gear, tear gas and rubber bullets. Speaking to ABC News on Sunday, Mr Nixon said he had been “thunderstruck” by the police response. “The over-militarisation… The guns pointed at kids in the street. All of that I think instead of ratcheting down, brought emotion up,” he said.

Yet while the arrival of Capt. Johnson and his officers brought about a brief calm, by Friday night public anger flared again after police issued a statement saying Mr Brown had been a suspect in a robbery at a local convenience store. Ferguson police chief Tom Jackson later admitted that Darren Wilson, the officer who shot Mr Brown, was not aware he was a suspect at the time.

The authorities also released CCTV footage of the robbery, leading to accusations that they were trying to smear the victim. On Saturday Mr Nixon declared a state of emergency and ordered the nightly curfew from midnight to 5am; the Governor also criticised the release of the video, saying it “appeared to cast aspersions on a young man that was gunned down in the street.”

The details of Mr Brown’s shooting are still disputed: police said he reached for Wilson’s gun during an altercation inside a police car; witnesses insisted Mr Brown had his hands up when he was shot. A preliminary private autopsy was conducted on Sunday at the Brown family’s request by Dr Michael Baden, the former chief medical examiner for the City of New York.

Anthony Gray, a lawyer representing the family, said the trajectory of one of the two bullets that struck Mr Brown in the head was particularly noteworthy. “To have a shot that’s at a 90-degree angle from the top of his skull to the bottom of his chin, almost vertical, that sounds like an officer standing over him,” Gray said.

On Sunday US Attorney General Eric Holder announced that the Justice Department would also conduct its own autopsy on Mr Brown’s body due to “the extraordinary circumstances involved in this case”. President Barack Obama has directed the FBI to investigate Mr Brown’s death; 40 FBI agents reportedly went door-to-door at the weekend to collect information on the shooting.