Relatives of an Australian woman shot dead by a US policeman say they are concerned the incident may not have been investigated properly.
Justine Damond, 40, was killed after calling police to report a woman screaming outside her Minneapolis home in July.
Last week, a US prosecutor said investigators had not "done their jobs" in examining her death.
Ms Damond's father said he now felt "compelled" to comment on the case.
"We are deeply concerned about the possibility that the initial investigation was not done properly and with greatest integrity and sense of completeness," John Ruszczyk told reporters in Sydney on Thursday.
In a video released last week, Hennepin County Attorney Mike Freeman said he did not have sufficient evidence to charge Mohamed Noor, the officer who shot Ms Damond as she approached his police car in her pyjamas.
"Who didn't do their jobs? Investigators. And they don't work for me. And they haven't done their job," Mr Freeman said.
He later apologised for the comments, saying he did not know he was being recorded by activists who had confronted him over the case.
Mr Ruszczyk said Mr Freeman's comments cast doubt on the Minnesota Bureau of Criminal Apprehension (BCA) investigation.
He implored US prosecutors to continue a "rigorous" examination of evidence.
"Ignorance cannot prevail here," he said.
Officer Noor has not spoken to investigators about the shooting.
Ms Damond's death sparked outrage in Australia, where Prime Minister Malcolm Turnbull called it "inexplicable" and "a shocking killing".
The shooting also prompted protests in the US and led to the resignation of Minneapolis police chief Janee Harteau.