'She was going to stab me': Topic inquest

Lucy Hughes Jones
AAP

The police officer who shot dead a knife-wielding mentally ill woman outside a Sydney fast-food restaurant has told her inquest she was about to attack him.

Constable Ethan Tesoriero shot Courtney Topic, 22, in the chest near the West Hoxton Hungry Jack's car park in February 2015 after two other police tried to subdue her with pepper spray and a defective Taser.

The constable had received a police radio broadcast before midday on February 10 about a distressed young woman talking to herself, hitting herself on the head and pointing the large kitchen knife at her stomach.

But Const Tesoriero, who had only completed a one-day mental health course, said he couldn't recall any of those details as he and Probationary Constable Angela Tyson pulled up to Ms Topic in a police car with flashing lights and sirens blaring.

The court previously heard the Carnes Hill woman had been suffering a severe psychotic episode and likely had undiagnosed schizophrenia.

With gun drawn, Const Tesoriero repeatedly yelled as loud as he could for Ms Topic to drop the knife, he told Glebe Coroners Court on Tuesday.

But she ignored him and continued to pace from side to side while looking at the ground, he said.

Ms Topic's mother Leesa began sobbing in court when Const Tesoriero described the moment her daughter began advancing towards him.

A third police officer arrived and hit Ms Topic in the face with capsicum spray, but she only stumbled slightly before continuing to push Const Tesoriero back.

"Every turn that I made, she made," Const Tesoriero said.

The court previously heard Const Tyson tried to fire her Taser unsuccessfully when Ms Topic lunged and thrust the knife at Const Tesoriero.

"I thought that she was going to stab me," Const Tesoriero said.

He fired a single bullet to her chest, and although officers carried out CPR she died soon after.

The inquest, before Deputy State Coroner Liz Ryan, resumes on Thursday.