MINNEAPOLIS (AP) — Sen. Amy Klobuchar asked a top Minnesota prosecutor to initiate an independent investigation into the case of Myon Burrell, a black man who as a teenager was sentenced to life in prison after the stray-bullet killing of an 11-year-old black girl.

The NAACP and other racial justice groups praised the decision Thursday, saying it was the first step to finding real justice. But Hennepin County Attorney Mike Freeman pushed back, indicating an internal review by his own office might be good enough.

“As you are aware," Klobuchar wrote to the county attorney, ”significant concerns about the evidence and police investigation have been raised by a press investigation, by members of the Hennepin County community, and by Myon’s family."

In calling for “an independent investigation and independent review,” Klobuchar was yielding to increasing community pressure to reopen a case that dogged her unsuccessful Democratic presidential primary run. The Associated Press last month published a story exposing major flaws in the police probe and prosecution, raising questions as to whether Burrell may have been wrongfully convicted when he was 16.

Burrell, now 33, has spent more than half his life in prison. He told the AP in a recent prison interview that he "slipped into a dark place” when he was sentenced and thought that it didn’t matter to the world if he was guilty or innocent.

Klobuchar made her decision after meeting with Burrell's family on Tuesday.

“As I told them,” she wrote, “I believe that if any injustice was done in the quest for justice for Tyesha Edwards, it must be addressed.”

Edwards was killed on Nov. 22, 2002 while doing homework at her dining room table.

Klobuchar, throughout her political career, has used Burrell’s conviction to trumpet her commitment to racial justice, but she has faced increasing criticism from the African American community in Minnesota and national media following the AP report.

She cancelled a rally in her home state two days before the Minnesota Democratic primary after around 100 protesters took over the stage, waving signs and chanting “Free Myon!” Less then 24 hours later, she ended her campaign and endorsed former Vice President Joe Biden.

The head of the Minnesota NAACP, Leslie Redmond, lauded Klobuchar's latest move.

“The acknowledgment that this case warrants a review is the first step to righting the wrongs that were committed against Myon and the victim’s family," she said. ”As the calls for an independent investigation grow, we expect that Attorney Mike Freeman will have the courage to assure justice and liberty is fairly granted.”

Burrell was convicted twice, once when Klobuchar was the chief prosecutor. After the first verdict was reversed, he was convicted a second time under Freeman’s supervision.

The AP pointed to a lack of physical evidence in the case, a single eyewitness who provided contradictory accounts of the shooting and the heavy reliance on jailhouse informants who received generous sentence reductions or cash. Some informants have since recanted. Reporters also spoke to another man who said he was in fact the shooter.

Klobuchar responded to the report by saying, repeatedly, that any new evidence, or flawed old evidence, should be reviewed. But her letter to Freeman was her first concrete step toward making that happen. In her letter, she also said she supports sentencing review efforts taking place in other parts of the country “to allow the system to look back at sentences to ensure that they are just.”

Last week, Freeman released a statement expressing confidence in the work of police and prosecutors in Burrell’s case, saying he still believed they had the right guy.

On Thursday, he was satisfied by a monthslong, ongoing review by his office. He said he welcomed any new information on the case.

Advocacy groups, including Black Lives Matter and the Racial Justice Network, said that was not good enough.

“In light of the disturbing statement and video that you released last week doubling down on justifying Myon Burrell’s unjust conviction, we have little faith that you or anyone from your office would conduct a fair, thorough, and impartial investigation," they wrote. “The high profile nature of this case, the political implications, allegations of police misconduct, and the cause of justice require an independent investigation into Myon Burrell’s claims of actual innocence.”