Michael Brown's parents say white police officer 'wanted to kill someone'

The parents of Michael Brown have lashed out at the white police officer who gunned down their son, saying the policeman "wanted to kill someone" on the day he shot their unarmed black teenager.

Speaking after a grand jury cleared him of the August killing, Officer Darren Wilson said he had "a clear conscience" and would have opened fire again if the confrontation on a Ferguson street was replayed.

His words were met with fury by protesters in this Missouri city and condemned by Michael Brown Senior and Lesley McSpadden, the parents of the dead 18-year-old.

"I don't believe a word of it," Ms McSpadden said, when asked about the claim her son had thrown the first punch and been killed while charging down the street towards Mr Wilson.

"[Mr Wilson] didn't do what he had to do, he did what he wanted do ... he wanted to kill someone."

Ms McSpadden wept as she said that her son's body was left lying in the street in the summer heat for so long that his organs could not be donated.

As Mr Brown's parents push for national legislation forcing police to wear cameras on their uniforms, Mr Wilson said he was hoping to one day leave hiding and resume a normal life.

The officer, who recently married and whose wife is pregnant, said Mr Brown had tried to wrestle his gun out of his hands during a struggle and that he believed the six-foot, four-inch teenager was capable of beating him to death.

"The reason I have a clean conscience is that I know I did my job right," he said.

Witnesses who testified before the grand jury offered different accounts of the August 9 shooting, with some saying Mr Brown had his hands up in surrender when he died and others claiming he charged at Mr Wilson.

The US Justice Department is still investigating the case and federal prosecutors could in theory bring civil rights charges against Mr Wilson, but that is widely considered unlikely.

Thousands of heavily armed National Guard troops and riot police surged onto the streets of Ferguson on Tuesday, successfully preventing a second night of widespread violence.

While there were intermittent clashes near the Ferguson police headquarters – and officers once again filled the cold night air with tear gas – there was no repeat of the arson and looting seen on Monday.

A column of armoured vehicles succeeded in dispersing what authorities called "an unlawful gathering" on South Florissant Road while a police helicopter circled overhead, shining its powerful lights on the scattered demonstrators.

Police arrested 45 people but mainly for minor offences and said there was far less gunfire than the night before. "Generally, it was a much better night," said John Belmar, chief of St Louis County police.

Soldiers armed with assault rifles and backed by armoured Humvees lined the streets and protected businesses which on Monday had been left exposed to rioters on West Florissant Road.

Lyen Tam, the owner of a Chinese takeaway, paused between serving a steady stream of customers to say that the troops' presence had made a difference.

"We feel safer, especially when we're leaving," she said. "I wish they were here Monday." The St Louis region remained tense and two FBI agents were wounded during a shoot-out apparently unrelated to the Ferguson unrest.

Police also continued to investigate the murder of Deandre Joshua, a 20-year-old African-American found dead in a car on Tuesday morning just a few hundred yards from where Mr Brown was killed in August.

While the streets of Ferguson were quieter, mass protests against the grand jury decision reportedly spread to more than 100 cities from New York to Los Angeles.

Thousands of demonstrators snarled traffic in Manhattan, while in California protesters gathered around the Los Angeles Police Department headquarters.

In Minneapolis, a woman was injured after a car ploughed into a line of protesters. The woman was dragged for several feet under the car's front left tyre but sustained only minor injuries. The driver, a 40-year-old man, is cooperating with police and has not been charged.

Meanwhile, in Cleveland demonstrators blocked roads in protest at the death of a 12-year-old black boy killed by police last weekend as he played with a toy gun.