Prosecutors in the US city of St. Louis have announced that they will not prosecute a former police officer who shot a black juvenile in 2014.
The killing of Michael Brown in Ferguson sparked weeks of protest.
It also led to the founding of the Black Lives Matter movement.
Prosecutors said the five-month review of the case did not find enough evidence to charge a murder or murder to former officer Darren Wilson.
In 2015, the Ministry of Justice concluded that he had fired in self-defense.
Why was Michael Brown killed?
The exact details of what happened that day remain disputed by police, eyewitnesses and family members.
It is known that around noon on August 9, 2014, Mr. Wilson was driving a police car and met Mr. Brown and a friend who was walking down the street.
- Who was Michael Brown?
- As one shooting provoked national protests
A few minutes later, 18-year-old Mr. Brown died, suffering from at least seven wounds, said County Attorney Bob McCulloch. His body lay on the street for four hours before it was removed.
Mr. Wilson fired a total of 12 bullets, although investigators were not sure how many of those 12 hit Mr. Brown. One injury can be a repeated wound.
Witnesses said Mr Brown had his hand up when the shot was fired, but investigators said the evidence suggested that this was not the case.
Nationwide protests were sparked by the murder and the decision not to blame the officer. Two police officers were shot dead in the riots that passed through Ferguson.
What’s the latest?
Findings, after re-examining the case, again found that Mr Wilson should not be charged.
“Can we prove without a doubt that a crime has taken place?” New prosecutor Wesley Bell told a news conference. “There is no answer.”
However, Bell said the investigation could not deprive the officer of the officer who resigned shortly after the killings.
“There are many things in which Darren Wilson could handle the situation differently, and if he did, Michael Brown could be alive,” he said.
The announcement comes with a continuing protest against racism and police brutality following the death of unarmed black George Floyd in Minneapolis, Minnesota in May.