Protests after white ex-police officer is acquitted of black man's murder

More than a dozen arrests were made, and several officers were hurt as the day went on.

Stockley, who was charged with first-degree murder, insisted he saw 24-year-old Anthony Lamar Smith holding a gun and felt he was in imminent danger. Prosecutors said the officer planted a gun in Smith's car after the shooting.

In an interview with the St Louis Post-Dispatch, Stockley said he understands how the video of him fatally shooting Smith looks bad to investigators and the public, but he said the optics have to be separated from the facts and he did nothing wrong.

"I can feel for and I understand what the family is going through, and I know everyone wants someone to blame, but I'm just not the guy," he said.

Stockley, 36, asked the case to be decided by a judge instead of a jury. Prosecutors objected to his request for a bench trial.

"This court, in conscience, cannot say that the State has proven every element of murder beyond a reasonable doubt or that the State has proven beyond a reasonable doubt that the defendant did not act in self-defence," St Louis Circuit Judge Timothy Wilson wrote in the decision .

In a written statement, St Louis Circuit Attorney Kim Gardner acknowledged the difficulty of winning police shooting cases but said prosecutors believe they "offered sufficient evidence that proved beyond a reasonable doubt" that Stockley intended to kill Smith.

Assistant Circuit Attorney Robert Steele emphasised during the trial that police dashcam video of the chase captured Stockley saying he was "going to kill this (expletive), don't you know it".

Less than a minute later, the officer shot Smith five times. Stockley's lawyer dismissed the comment as "human emotions" uttered during a dangerous police pursuit. The judge wrote that the statement "can be ambiguous depending on the context".

Stockley, who left St Louis' police force in 2013 and moved to Houston, could have been sentenced to up to life in prison without parole.

Efforts at civil disobedience were largely unsuccessful. When several demonstrators tried to rush on to Interstate 64, they were blocked on an entrance ramp by police cars and officers on bikes. When they tried to enter the city's convention centre, the doors were locked.

At times, things escalated. Earlier in the day, protesters stood in front of a bus filled with officers in riot gear, blocking it from moving forward. When officers began pushing back the crowd, protesters resisted and police responded with pepper spray. Later, protesters surrounded a police vehicle and damaged it with rocks. Some in the crowd threw rocks and pieces of curbing at police who tried to secure the vehicle. That led to officers using pepper spray again.

As night came, hundreds of protesters moved to St Louis' upscale Central West End section, where they marched and chanted as people looked on from restaurants and hospital windows lining busy Kingshighway. The group tried marching on to I-64 again, but police blocked their path.

Following a mostly silent sit-in, protesters resumed marching. Some demonstrators burned an American flag as others cheered.

After protesters broke a front window and splattered red paint at St Louis mayor Lyda Krewson's home, police in bulletproof vests and helmets arrived and demanded they get off the lawn and out of the street in front of the house. Officers used tear gas to try to move the crowd out of the area.

Ms Krewson had called for calm and understanding ahead of the verdict and later said she was appalled by what happened to Smith and "sobered" by the outcome.

AP