An Australian woman who taught meditation classes has been killed by a US police officer responding to a 911 call in Minneapolis.
The Minnesota Department of Public Safety said police responded to "a call of possible assault" when "at one point an officer fired their weapon, fatally striking a woman".
Officials said the officers' body cameras were not turned on at the time of the Saturday shooting.
The victim has been identified by Australian officials as Justine Damond.
The 40-year-old was living in Minneapolis with her fiancé, and she had called 911 to report a noise near her home when the incident occurred, reports said.
A County Medical Examiner's office says she died of a gunshot wound to the abdomen and has ruled the manner of death is homicide.
The Minneapolis Star-Tribune has reported, citing three sources, that Ms Damond was dressed in pyjamas and had approached the driver's side door of the police car and was talking to the officer at the wheel.
The officer in the passenger seat, identified by local media as Mohamed Noor, reportedly drew his gun and shot Ms Damond through the driver's window, the newspaper reported.
Mr Noor's lawyer, Tom Plunkett, confirmed on Monday that his client had fired his weapon, killing Ms Damond.
"We take this seriously with great compassion for all persons who are being touched by this," he said in a statement to CBS News.
It's still not clear why the officer involved drew his weapon or why both officers had their body cameras turned off.
Ms Damond, nee Justine Ruszczyk, taught meditation classes at the Lake Harriet Spiritual Community.
She was using the surname of the man she was expected to marry in August, Don Damond, according to the Minneapolis Star Tribune.
Ms Damond studied to be a veterinarian before she relocated to the US, where she was believed to have been for at least the last three years.
A man claiming to be Ms Damond's stepson said in a Facebook video that she was the one who alerted authorities after she heard a sound in the alleyway.
"Basically, my mom's dead because a police officer shot her for reasons I don't know," said the man, named Zach.
"I demand answers. If anybody can help, just call the police and demand answers. I'm so done with all this violence," he said.
"America sucks. These cops need to get trained differently. I need to move out of here."
The Department of Public Safety's Bureau of Criminal Apprehension said an investigation was under way and authorities were looking into whether there was any video of the incident.
Minneapolis mayor Betsy Hodges said in a statement she was "heartsick and deeply disturbed by what occurred last night".
Alison Monaghan, a friend who trained Ms Damon in alternative therapies, told the ABC she was "the most beautiful person", who moved to the US to "follow her heart" for a "new life".
About 200 neighbours, family members and residents shocked by the shooting gathered for a vigil on Sunday night where she died.
"I mean ask anybody here, they're shocked," Ms Damond's student Corey Birkholz told CBS News.
He described Ms Damond as "a very conscious, loving person and you wouldn't associate that with a gunshot in an alley".
The two officers involved in the shooting are on paid administrative leave.
The Australian Department of Foreign Affairs said in a statement that it was a difficult time for the family, who were trying to come to terms with the tragedy.
- BBC / ABC