The majority of the Minneapolis officers subpoenaed to testify before a grand jury in the fatal police shooting of an Australian woman were the trainers or educators of the officer who fired his weapon, according to the head of the Minneapolis police union.

More than 30 officers have been subpoenaed to testify as prosecutors decide whether to charge Officer Mohamed Noor in the July death of Justine Ruszczyk Damond, a 40-year-old life coach who was engaged to be married.

She was shot in an alley as Mr Noor and his partner responded to her 911 call about a possible sexual assault behind her home.

Bob Kroll, president of the Minneapolis Police Federation, said the majority of those testifying were Mr Noor’s trainers or educators in the police academy, according to the Star Tribune.

When prosecutors question the witnesses, they will likely ask how Noor was trained for a situation such as the one involving Ms Damond, said Ramsey County Attorney John Choi, who is not involved in the case.

“And then you’re asking yourself what would a reasonable officer do under those circumstances with that training,” Mr Choi told the newspaper.

The officers were summoned to testify before the grand jury on Tuesday.

Noor’s partner, Officer Matthew Harrity, witnessed the shooting and has been subpoenaed to testify. Noor has not spoken to investigators.

Officer Noor had little more than two years experience in the police force. Photo: MPD

Hennepin County Attorney Mike Freeman had previously said he would no longer use grand juries in police shooting cases because they lack transparency.

He has declined to confirm a grand jury is investigating the Ms Damond case, citing the secrecy of such proceedings, but said he still intends to make his own decision on whether to charge the officer.

The move to use a grand jury became public after officers received subpoenas and about a month after Mr Freeman said he didn’t have enough evidence and more investigation was needed.

Mr Harrity, Mr Noor’s partner, has told investigators that he was startled by a loud noise right before Ms Damond appeared at the driver’s side window of their police SUV on July 15.

Mr Harrity, who was driving, said Mr Noor then fired his weapon from the passenger seat and through the open window, shooting Ms Damond.

Ms Damond, who was unarmed, died of a gunshot wound to the abdomen.

Mr Freeman would be required to prove Noor’s actions in shooting Ms Damond were “culpably negligent” if he were to pursue manslaughter charges under Minnesota law, according to experts.

He also needs to prove Mr Noor’s actions were objectively unreasonable at the time.