Former Acting U.S. Attorney General Sally Yates will lead an independent investigation into whether Minneapolis police officers crossed a line and urged paramedics to inject members of the public with ketamine, a powerful sedative.

"The people of Minneapolis have spoken and we've heard their message loud and clear, which is, we need to get to the bottom of what happened and we need to do it in a transparent and accountable way completely free from any interference from officials in the city," Mayor Jacob Frey said Friday.

Yates was the Justice Department's second-in-command at the end of the Obama administration and acting attorney general under President Donald Trump until he fired her for refusing to defend the travel ban executive order in late January 2017. Last month, she announced she was returning to her old law firm to help conduct investigations.

"She's got a record that's beyond reproach," Frey said. "It speaks for itself. Just a long history of commitment to unearthing the truth and delivering justice, and that's exactly what we need now."

Frey and Minneapolis Police Chief Medaria Arradondo said earlier this week they planned to appoint an independent investigator to examine the ketamine cases, following a Star Tribune story that included excerpts from a draft report authored by staff from the city Office of Police Conduct Review.

The draft report cited several examples of police asking paramedics to sedate people with ketamine on calls where both came to the scene, and questioned whether officers should be suggesting medical care.

"Between 2016 and 2017, MPD officers explicitly asked EMS to provide ketamine, either when calling for EMS services or upon arrival of the ambulance eight times," states the report. "Also, MPD officers assisted [EMS workers] while they injected individuals with ketamine" by holding them down while the EMS worker reportedly gave the shot.

Several of these cases cited in the report resulted in serious medical complications, including some needing intubation to breathe.

The report has not been made public, but police command staff in May sent a departmental memo ordering officers not to make suggestions on the use of sedatives.

On Friday, Arradondo said he was concerned to learn about the alleged incidents. "It certainly does not fit into our core values," he said. "The mayor and I immediately had deliberate and intentional conversations on how this could potentially impact the public trust."

Arradondo said it was important to find a skilled investigator who could come with a high degree of credibility and impartiality. He said his role will be to provide Yates and her team with unfettered access to police records and to guarantee the cooperation of his department personnel.

The cost of hiring Yates will "be competitive with others of her caliber," but can't be determined until the investigation begins, Frey spokesman Mychal Vlatkovich said.

Several City Council members said they were "appalled" by the allegations in the draft report. A council committee ordered police oversight staff to complete their report so it can be published by late July, and for an independent review of the report.

Leadership for Hennepin Healthcare also asked for a review of cases involving its paramedics, and a spokeswoman for North Memorial Medical Center said it will also participate.

On Thursday, in a standing-room-only council committee meeting, more than a dozen people criticized the reported police conduct regarding use of ketamine.

In response to some of these comments, Arradondo said he examined data involving ketamine cases over the past five years and found only one example of the person who received ketamine actually being arrested. In the other cases, police responded to the scene along with paramedics, but the incident did not result in an arrest, he said.

"I think that's important, because I need to highlight that these are our community members in a medical crisis and it's not about arrests or suspicious activity or behavior," he said.

Andy Mannix • 612-673-4036