Minneapolis police chief Janee Harteau had faced criticism over her handling of the killing of Justine Damond last Saturday night, which ignited an international outcry.
She did not appear before TV cameras until Thursday, saying she had been on vacation at a remote mountain location.
The Midwestern city's mayor Betsy Hodges said she asked for the chief's resignation Friday and Harteau tendered it.
"I've lost confidence in the chief's ability to lead us further. And from the many conversations I've had with people around our city, especially this week, it is clear that she has lost the confidence of the people of Minneapolis as well," Hodges said in a statement.
In announcing her resignation, Harteau said she wanted to "let a fresh set of leadership eyes see what more can be done" to improve the police department.
Moments later the mayor announced her nomination of Assistant Police Chief Medaria Arradondo as Harteau's replacement. Arradondo has been the public face of the department during the crisis.
If the moves were meant to quell uproar in the city, they did not appear to work.
In an evening news conference the mayor held to speak further about the changes, an angry group of protesters interrupted the mayor within minutes of her taking the podium.
"We're not buying this," exclaimed one protester from the podium after the mayor left, having been shouted down by the crowd. "This is just a cosmetic change and we want institutional change."
The protesters were particularly angry about the lack of body camera footage of the shooting, and complained of a lack of police accountability.
"We don't want you as the mayor of Minneapolis anymore," another protester said. "You're ineffective as a leader."
There were street protests for a second day in a row on Friday, this time in downtown Minneapolis, following a march Thursday night on the streets of Damond's neighborhood to the south of downtown.
Damond, a 40-year-old meditation teacher and life coach, called police Saturday night after hearing noises she feared might have been those of someone getting raped.
Responding officer Matthew Harrity had been startled by a loud noise just before Damond approached the police car he was driving, prompting his partner Mohamed Noor to fire the fatal shot, authorities said.
The state's Bureau of Criminal Affairs (BCA), the agency investigating the shooting, said Friday that Noor continued to refuse an interview with authorities. But investigators located and interviewed a witness they had been seeking, the BCA said.
The witness had been bicycling near the scene of the shooting and had stopped to watch officers provide first aid. The BCA did not disclose what the witness told investigators.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)