'Shot for no reason': Aussie woman killed by US cops after call for help

Friends and family are demanding answers as to why US police shot dead a 40-year-old Australian woman.

The victim has been identified as Justine Damond, also known as Justin Ruszczyk, who was living in Minneapolis with her fiancé.

A devastated community are now trying to figure out how she was shot down after calling police to report an alley way assault.

Her 22-year-old step-son whose father was engaged to be married to the the Australian in August, said she was shot "for no reason".

"Basically my mom's dead because a police officer shot her for reasons I don't know," he said in a heartbreaking video moments after the shooting.

"I demand answers. If anybody can help, just call police and demand answers," he added.

"I'm so done with all this violence, America sucks."

Police bodycameras were switched off, while the dashcam was reportedly not working at the time of the shooting.

Two Minneapolis police officers responded to a 911 call of a possible assault just north of the 5100 block of Washburn Avenue South just before 11.30pm Saturday, Minneapolis police confirmed in a statement.

A sign at the scene of the crime that reads "why did you shoot and kill our neighbor and friend?”

A vigil is currently underway with hundreds of community members flocking to the scene of the crime, describing her as the "most loving, beautiful woman”.

"They [police] are trained to execute, shoot and kill, she didn't deserve to be dead," a visibly distressed woman said during the vigil.

Australia's Department of Foreign Affairs and Trade said Australian Embassies or Consulates have no authority to intervene in local judicial matters.

In cases involving the deaths of Australians overseas, consular assistance may include support and guidance to families and liaison with local and Australian authorities to assist with funeral arrangements or repatriation of remains, they told 7 News Online

More to come.