Veteran Hornsby police sergeant Richard Jackson said he "obviously rushed" the quality control process regarding the allegations made by Olga Edwards on December 29, 2016.

The inquest into John Edwards' July 2018 murders of his two teenagers was told Ms Edwards recounted to a Hornsby officer how her ex-husband had assaulted Jack and Jennifer in 2015.

The officer - an 18-year veteran used to teaching kids road safety - mistakenly dubbed the mother as the victim and attributed the start date to March 2016, when Ms Edwards and the children left the family home.

With it already "appraised" by a supervisor on the day, Sgt Jackson spent less than two minutes verifying the report the next day.

"I've definitely rushed it," he told a supplementary hearing of the inquest on Friday.

While disagreeing he should have spent 10 to 15 minutes per report, he agreed two minutes was "inadequate".

The inquest has previously heard Sergeant Rodney McCaffery appraised the report without reading it, relying on a verbal account by report author Senior Constable Brooke Cooper.

Ms Edwards had reported her husband had hit and kicked Jack over the use of an iPod, hit Jack for touching CDs and slapped Jennifer in the face for not going to bed when told.

Sgt Jackson initially stood by Sen Const Cooper's marking of Ms Edwards as the victim in a report focused on assaults upon children "because Ms Edwards had come in to report a property dispute".

He said her being locked out of the marital home in March 2016 "was a property dispute and it was ongoing".

"Without further investigation, I think the event was recorded correctly," he said.

But later he later agreed the children should have been recorded as victims.

The event was also incorrectly marked "domestic violence - no offence" and Edwards was labelled "person named", not "person of interest" - the term used for suspected perpetrators.

"I didn't check to see that the incident field was filled out with his name as a suspect," Sgt Jackson, who joined the police in 1995, said.

After placing weight on the Edwards' ongoing family law proceedings, Sen Const Cooper took no action besides telling Ms Edwards to bring the children into the station.

"At the time, I believed that Sen Const Cooper was making the inference that Ms Edwards was being dishonest in her report," Sgt Jackson said.

The inquest on Friday heard that, with the report marked "domestic violence - no offence", the sergeant's verification meant the case was effectively marked "no further investigation required".

"Is it fair to say that correctly characterising the incident is a critical part in the investigative process?" Christopher Mitchell, counsel assisting the coroner, asked.

"Yes, it is," the sergeant replied.

Edwards, 67, was given a gun licence in 2017 and then used two pistols he purchased legally to kill his estranged children and himself.

Devastated by her children's deaths, Ms Edwards took her own life in December 2018, aged 37.

The inquest will convene for one more session in November for further examination of independent children's lawyer, Debbie Morton, who was tasked to advocate for Jack and Jennifer in family law proceedings.

Coroner Teresa O'Sullivan is due to hand down her findings on December 18.

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Australian Associated Press