Devastated fiancé says Aussie woman killed by police called 911 to report 'sex assault'

The heartbroken fiancé of a Sydney woman says he has been given no information as to why police shot her dead near their Minneapolis home.

Justine Ruszczyk Damond was shot dead about 11.30pm local time on Saturday after two officers responded to a report of a possible assault.

Now the man she was supposed to marry next month said he has been completely left in the dark by authorities.

"Our hearts are broken," Don Damond said in an emotional press conference.

"As you know, it was her who called 911 on Saturday evening, reporting what she believed was an act of sexual assault occurring nearby.

Standing alongside his 22-year-old son Zach, Justine's fiancé Don Damond addressed the media. Source: 7 News
She was engaged to marry her 50-year-old partner Don Damond in August.

"Sadly, family has been provided no additional information from law enforcement regarding what happened after police arrived.

"We have lost the dearest of people and we are desperate for information.

"It is difficult to fathom how to go forward without her."

Thanking their friends and family in both Australiand and the US, Mr Damond said "piecing together her last moments before the homicide would be a small comfort" as they grieve.

"She was a teacher to so many and living a life of openness, love and kindness," he added.

Justine Damond was shot dead by police outside her Minneapolis home. Source: AAP
Officer Mohamed Noor was allegedly sitting in the passenger seat of a police car when leaned over and shot across his partner. Source: Minneapolis Police Department
Mohamed Noor joined the department in March 2015. Source: Facebook

The junior police officer who shot the 40-year-old has since been named as Mohamed Noor.

Officer Matthew Harrity was driving the car, however neither had their body cameras switched on.

It's believed Officer Noor reached over his partner and fired out the driver's window, fatally striking the Sydney 40-year-old, with suggestions he may have thought her phone was a gun.