A woman who died after an hours-long siege near Newcastle last week was killed by injuries sustained from a bean bag round fired by policea gunshot wound, according to interim post-mortem results.
Just after 12.30pm on September 14, police were called to a block of units in Stockton after reports a woman was allegedly threatening a real estate agent with an axe.
Krista Kach, 47, allegedly also threatened officers with the axe and barricaded herself inside a unit.
After negotiators spoke with Kach for several hours, tactical officers entered the unit, and they deployed a single bean bag round and a Taser during the arrest.
A bean bag round, classified as a "less than lethal" option by police, is fired from a regular shotgun and is designed to briefly immobilise a suspect during an arrest while being less damaging than a bullet.
The deployment and options available to tactical police must be approved by an assistant commissioner at every incident.
Kach was able to walk to an ambulance, but her condition deteriorated and she was taken to hospital, where she later died.
NSW Police Acting Commissioner David Hudson said today the interim post-mortem results, which he had been permitted by the coroner to reveal, indicated the woman had suffered a gunshot wound to the chest.
"It would appear that the bean bag round has entered the body of the deceased and ended up striking her heart," Hudson said.
Hudson said all uses of bean bag rounds had been stopped in NSW while a review was underway.
He said bean bag rounds had been used by NSW police 15 times this year, with no fatal results before Stockton.
"The makers of the device don't specify a range for use of bean bag round," he said.
That will form part of the review.
Hudson said police were also examining how to deal with scenes where the presence of uniformed officers might escalate the situation.
A critical incident investigation into the Stockton siege is currently underway.
"We were assured that the police would look after our mother and that she would be cared for by a hospital and qualified medical professionals," the family said in a statement.
"Our mother was not a dangerous person, she has lived through difficult circumstances but she was a loving and capable person that cared for people and her family.
"The only person in danger when the police broke into our mother's home and the many hours leading up to that moment was our mother."
The family said Kach was a strong independent woman who cared deeply about her loved ones and community.
"She had experienced some mental distress in her life because her life was quite tough, but she was well connected with her own health and her family were advocating for her wellbeing with the police prior to the shooting incident," the family said.