Prosecutors in the U.S. city of St. Louis have said they will not file charges against a former police officer who murdered a black teenager in 2014.
The killing of Michael Brown in Ferguson sparked weeks of protests.
It also marked the founding of the Black Lives Matter movement.
Prosecutors said a five-month review of the case had not found enough evidence to bring murder or homicide charges against former officer Darren Wilson.
In 2015 the Justice Department concluded he had fired in self-defense.
Why did Michael Brown die?
The exact details of what happened that day remain disputed by police, eyewitnesses and relatives.
What is known for sure is that around noon on August 9, 2014, Mr. Wilson was driving a police car and bumped into Mr. Brown and a friend walking down a street.
- Who was Michael Brown?
- As a shot triggered national protests
Minutes later, Mr. Brown, 18, died, suffering at least seven gunshot wounds, according to County Attorney Bob McCulloch. His body was on the street four hours before removing it.
Wilson fired a total of 12 bullets, though investigators did not know exactly how many of the twelve shots hit Mr. Brown. An injury may have been a readmission injury.
Witnesses said Mr Brown had his hands raised when he was shot, but investigators said evidence suggests this was not the case.
Protests across the country led to the killing and the decision not to charge the officer with murder. Two police officers were shot when riots broke out through Ferguson.
The findings following a re-examination of the case proved, once again, that Mr. Wilson should not be charged.
“Can we prove beyond a reasonable doubt that a crime occurred?” new prosecutor Wesley Bell said at a news conference. “The answer to that is no.”
However, Mr Bell said the investigation could not exonerate the officer, who left his life shortly after the massacre.
“There are so many points where Darren Wilson could have handled the situation differently, and if he had, Michael Brown could still be alive,” he said.
The announcement comes in the wake of protests against racism and police brutality following the death of George Floyd, an unarmed black man, in Minneapolis, Minnesota, in May.