Minnesota Sen. Amy Klobuchar on Thursday asked the Hennepin County attorney to pursue "an independent investigation" into the 2002 killing of 11-year-old Tyesha Edwards amid new questions raised over the conviction of a black teenager in the case.

The request came a month after an Associated Press investigation raised questions about the conviction of Myon Burrell, who was 16 at the time when Klobuchar was Hennepin County attorney. The case was picked up by the national media and became a flash point of criticism by a group of Twin Cities activists during the final days of her presidential campaign.

"As you are aware, 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," Klobuchar wrote to Hennepin County Attorney Mike Freeman. "For that reason I believe that your office should initiate an independent review of the case and the evidence."

In a response, Freeman's office issued a statement saying that attorneys from his office met on Feb. 24 with Burrell's lawyer "and committed to reviewing the case file and the new information" that his attorney provided. "That review is ongoing."

The County Attorney's Office said that it has conducted a "significant review" of all the evidence of the Burrell case over the past several months. It also said it publicly requested any new information concerning the case and have reviewed the issues raised. "We have previously offered to review any new and additional evidence," the office said.

Freeman's review, however, seems to fall short of the independent review now sought by Klobuchar. "In addition to my request for a review of the new and old evidence in this case, I am asking you to call for an independent investigation and an independent review of the case," she wrote. She noted that other prosecutors' offices now include "conviction integrity" units, something she supports.

Klobuchar had called earlier for the case to be reviewed as she came under criticism on the campaign trail. But Thursday's letter was her first formal request as a U.S. senator. It also was her first significant public action since ending her bid for the Democratic nomination on Monday and endorsing former Vice President Joe Biden.

In the letter to Freeman, her successor, Klobuchar said she met with Burrell's family this week and told them that if any injustice was done "it must be addressed." Burrell remains behind bars serving a life term.

His supporters had stormed a Klobuchar rally in St. Louis Park on Sunday on what turned out to be the last full day of her campaign. The demonstration forced her to cancel the planned homecoming event.

Nekima Levy Armstrong, a civil rights attorney and activist, said Thursday that she met with Klobuchar along with Burrell's family and Minneapolis NAACP President Leslie Redmond.

She said "this was the most sincere response that I have seen from Senator Klobuchar since concerns have been raised about the wrongful conviction of Myon Burrell."

"It is a strong signal that she understands that there are significant problems with our criminal justice system in Hennepin County," Levy Armstrong said. "These are concerns that African-Americans and other people of color have been raising for years, but to have a person in her position openly acknowledge that is something that you rarely see."

Burrell was convicted in 2003 when Klobuchar served as Hennepin County attorney. He was granted a new trial before being convicted again in 2008 when Freeman ran the office.

The AP investigation raised questions about the credibility of jailhouse informants, the lack of physical evidence and alleged missteps by investigators. It also quoted a man who said he was responsible for firing shots at a rival gang member that accidentally struck Edwards. A bullet struck the girl while she was doing homework at the dining room table of her south Minneapolis home.

Freeman previously defended Klobuchar's handling of the Burrell case as it came under new scrutiny during the campaign. In a statement, he pointed out that she was not the trial attorney on the case and that Burrell's conviction "should not be treated like a political football."

But critics noted that over the years and during her campaign, Klobuchar had cited the investigation of Edwards' death as an example of her record of service as a prosecutor between 1999 and 2007. The death of Edwards, who was black, had been a topic of deep consternation in the black community at the time.

Klobuchar wrote in her letter that while she could no longer "order an independent review of this case, I believe that justice requires an independent investigation."

Levy Armstrong, who had called earlier for Klobuchar to end her presidential campaign over the case, cited the senator's call for a new investigation as potentially opening "the door for justice for Myon Burrell."

"This man has been crying out for almost two decades for people to just pay attention …," Levy Armstrong said. "And today with this letter, Amy Klobuchar is paying attention and giving voice to his concern from a very powerful platform."

Stephen Montemayor • 612-673-1755

Twitter: @smontemayor