THE Minneapolis police union boss has penned an extraordinary letter in support of the cop who shot dead Australian woman Justine Damond, saying prosecutors should not take into account that she was a “fine young woman”.

Ms Damond, a 40-year-old bride-to-be, was shot dead by police officer Mohamed Noor in Minneapolis on July 15 after she called 911 to report a possible sexual assault.

Writing in the Star Tribune, Minneapolis Police Officers Federation president Bill Kroll argued that Hennepin Country attorney Mike Freeman showed a “lack of professionalism” when he said on Sunday he was “saddened by the death of this fine young woman” and that the shooting “shouldn’t have happened”.

Mr Kroll wrote that Mr Freeman’s comments demonstrated he was “focusing on the status of the person lost rather than the events leading to a tragic loss”.

“We want an assurance that Noor will not be charged simply on the basis of Damond’s status as a fine young woman in a nice neighbourhood,” Mr Kroll wrote.

“The status of the deceased as a fine young woman, while true, is not and should not be part of an objective decision to charge anyone with a crime.

“This case is tragic, and so are the too many other deaths that have occurred in our city.

“This comment brings Freeman’s objectivity into question.”

Mr Kroll appeared to be speaking out due to violence against cops in the city.

“Police officers are being killed at an increasing rate,” he wrote.

“Worse, irresponsible comments by public officials are fuelling the creation of police widows and widowers.”

Mr Noor has not been detained over the shooting and he is yet to answer any questions from authorities about what happened that night.

The independent investigator into the incident, the Minnesota Bureau of Criminal Apprehension, turned its findings over to Mr Freeman on Tuesday and he will now determine whether there is enough evidence to bring charges against Mr Noor.

Ms Damond’s family has been vocal in calling for a transparent investigation where there “is no stone left unturned”.

“We trust that the Hennepin County attorney’s determination will be based on an astute assessment of the facts,” the family wrote in a statement this week.

Investigators have determined that Mr Noor shot at Ms Damond across his partner and out of a police car door where she was standing in her pyjamas.

— with AAP