No charges will be brought against the former Ferguson police officer who shot and killed Michael Brown, an unarmed Black teenager, in 2014, St. Louis County’s top prosecutor announced Thursday.

The shooting set off a months-long uprising in the Missouri city that reverberated around the country, spotlighted racial inequality and police brutality, and helped launch the Black Lives Matter movement. The decision not to charge Darren Wilson, the White former officer, comes amid another round of nationwide protests over law enforcement treatment of Black people, sparked by the killing of George Floyd in Minneapolis.

The prosecutor, Wesley Bell — recently elected on a platform of reform — said his office conducted a five-month independent reexamination of the case and determined there was not enough evidence to bring charges.

“This is one of the most difficult things I’ve had to do as an elected official,” Bell, the county’s first Black prosecutor, said at a news conference Thursday. “Michael Brown’s death exposed to the nation a deep-seated and long-standing pain felt by the greater St. Louis community and the entire country.”

Bell said his office reviewed witness statements, forensic reports and other evidence to determine whether they could prove Wilson committed murder or manslaughter.

“The only question is whether we can prove beyond a reasonable doubt that a crime occurred,” Bell said. “The answer to that question is no.”

But the investigation “does not exonerate Darren Wilson,” he added.

Brown was 18 years old, a recent high school graduate, when Wilson confronted him and a friend on a street in Ferguson. Wilson later testified that he was responding to a theft call from a nearby store. A struggle began that led to a chase down the road and ended when Wilson shot Brown at least six times, claiming he did so in self-defense. Authorities left Brown’s body in the street for hours after the shooting.

Bell’s predecessor, Robert McCulloch, did not charge Wilson and instead sent the case to a grand jury, which declined to indict Wilson, who resigned from the department days later.

The Justice Department also declined to press charges, but investigators published a scathing report on Ferguson’s police department and court system, blasting law enforcement for a “pattern of unconstitutional policing” and actions that “reflect and exacerbate existing racial bias.”

After Bell took office in 2019, Brown’s family and civil rights advocates pushed him to investigate again, and the prosecutor reopened the case early this year. Bell’s announcement angered some of Ferguson’s longtime activists, who criticized him for not going further than McCulloch.

“I’d have to believe the criminal system was ever built to protect Black people in order to be disappointed,” tweeted Brittany Packnett Cunningham, a Ferguson activist and member of President Barack Obama’s Task Force on 21st Century Policing. “I finally just sat down from running around, and it hit me that I’ve got no more shock left. #MikeBrown’s family deserves so much more.”

Ashley Yates, who was an organizer in Ferguson when Brown was killed, responded to Bell’s news conference announcing the decision in a tweet: “Not a single word about eliminating police murders. Not a single effort at restricting their ability to kill.”

As Bell left the podium, a man wearing a shirt that read, “Wesley Bell doesn’t care about Black people,” shouted that residents would vote the prosecutor out of office, as they’d done with McCulloch.

“It’s over,” he said, as police escorted him from the briefing room. “One term!”