Prosecutors in the U.S. city of St Louis have said they will not file charges against a former police officer who shot dead a black teenager in 2014.
The murder of Michael Brown in Ferguson sparked weeks of protests.
It also led to the founding of the Black Lives Matter movement.
Prosecutors said a five-month review of the case had not found enough evidence to file murder or murder charges against former officer Darren Wilson.
In 2015 the Department of Justice concluded that he had fired in self-defense.
Why did you kill Michael Brown?
The exact details of what happened that day remain controversial by police, eyewitnesses and family members.
What is known for sure is that around noon on August 9, 2014, Mr. Wilson was driving a police car and met Mr. Brown and a friend of his walking down a street.
- Who was Michael Brown?
- Like a shot sparked national protests
A few minutes later, 18-year-old Mr. Brown was dead, suffering at least seven gunshot wounds, according to District Attorney Bob McCulloch. His body lay on the street for four hours before being removed.
Mr Wilson fired a total of 12 bullets, although investigators were not clear how many of Mr. 12 shots were fired. Brown. An injury may have been a re-entry wound.
Witnesses said Mr Brown had his hands up when he was shot, but investigators said evidence suggested this was not the case.
Nationwide protests were sparked by the killing and the decision not to charge the officer with murder. Two police officers were shot as the riot passed through Ferguson.
What is the last?
The findings following a review of the case revealed, once again, that Mr Wilson should not be charged.
“Can we prove beyond a reasonable doubt that a crime occurred?” the new prosecutor, Wesley Bell, said at a news conference. “The answer to that is no.”
However, Mr Bell said the investigation could not exterminate the officer, who withdrew immediately after the killing.
“There are so many points at which Darren Wilson could have handled the situation differently, and if he had, Michael Brown could still be alive,” he said.
The announcement comes as protests continue against racism and police brutality following the death of George Floyd, an unarmed black man, in Minneapolis, Minnesota, in May.