The police officer who shot dead an Australian woman outside of her Minnesota home was already under investigation for 'violently' forcing a woman to hospital, court documents allege.

Mohamed Noor reached over and shot Justine Damond, 40, multiple times from the passenger seat of his squad car while she spoke to his colleague on the drivers side in a back alley behind her upscale Minneapolis home.

Both officer's bodycams were off and the squad car camera not recording, but an audio exchange between dispatch and the officers involved captures the chilling moments directly after she was killed at around 11.30pm on Saturday.

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Rookie police officer Mohamed Noor (pictured during 2015 induction to force), who shot dead Australian woman Justine Damond, 40, was already under investigation

Ms Damond was wearing pyjamas when she was shot multiple times from the passenger seat of Noor's squad car while she spoke to his colleague on the drivers side in a back alley

One officer can be heard saying he sees a 'female screaming behind a building' and 'one down' from the same location before saying they are performing CPR after 'shots fired'.

Noor, who joined the Minneapolis Police in March 2015, has reportedly had three complaints made against him in two years - including a lawsuit.

Two are from 2017 and one from 2016 is closed and according to Lou Raguse of Kare 11 is marked 'not to be made public'.

The lawsuit stems from a police call on May 25, 2017, when Noor and two other officers took a woman to hospital and she claimed that they carried out false imprisonment, assault and battery.

According to the ongoing lawsuit, the woman claimed that Noor 'grabbed her right wrist and upper arm' when moving her, leaving her 'immobilised'.

The woman, a retired social worker from Minneapolis, alleged that she had called 911 to 'report an unknown young male who was sitting on her retaining wall behind her house smoking marijuana.'

Officers followed up on her complaint but returned to her home at 8pm to carry out a welfare check after 'one or more relatives' allegedly complained to police that she had 'some sort of mental health problem'.

The woman alleged that she told the officers to leave but they forced a way into her home through a screen door and told her she was going to hospital for a 'mental health crisis.'

'Defendant Officer Noor grabbed Plaintiff's phone from her hand and then grabbed her right wrist and upper arm, thereby immobilizing her,' the complaint alleged.

She was eventually released from hospital one and a half hours later after a physician ordered that she was discharged, according to the court documents.

Noor, who joined the Minneapolis Police in March 2015, has reportedly had three complaints made against him in two years - including a lawsuit

An audio exchange between dispatch and the officers involved captures the chilling moments directly after Australian-born woman Justine Damond (pictured)

Ms Damond was shot dead by police after she called 911 to report a sexual assault happening in the alley behind her home

Noor issued a statement through attorney Tom Plunkett on Monday afternoon.

'Officer Noor extends his condolences to the family and anyone else who has been touched by this event. He takes their loss seriously and keeps them in his daily thoughts and prayers,' the statement read.

'He came to the United States at a young age and is thankful to have had so many opportunities. He takes these events very seriously because, for him, being a police officer is a calling. He joined the police force to serve the community and to protect the people he serves. Officer Noor is a caring person with a family he loves and he empathizes with the loss others are experiencing.

'The current environment for police is difficult, but Officer Noor accepts this as part of his calling. We would like to say more, and will in the future. At this time, however, there are several investigations ongoing and Officer Noor wants to respect the privacy to the family and asks the same in return during this difficult period.'