THE father who shot his two teenage children dead “in a premeditated and planned” attack after entering their home and later taking his own life in another location has been identified.

Financial planner John Edwards, 68, is believed to have entered the house on Hull Rd in West Pennant Hills and killed his son, 15, and daughter, 13, around 5.30pm on Thursday.

The children’s mother, Olga Edwards, 36, arrived soon after to a “horrific scene” in which her children had been murdered in a bedroom in a “targeted incident” related to domestic violence.

Ms Edwards, a solicitor, is understood to be suffering “severe shock” and is reportedly in the care of friends.

The gunman’s body was found in a Normanhurst home, 5km from the scene of the initial killings, about 12 hours after his two children were found dead, NSW Police confirmed on Friday. Edwards was the father of the children but did not live at the West Pennant Hills home, according to police.

NSW Police Acting Region Commander Brett McFadden told reporters the couple had been in a long-term relationship. However, this had broken down in recent years and Edwards lived separately from the rest of the family at the Normanhurst address where he died. Edwards — who described himself online as a “certified financial planner” — had owned the Normanhurst home since 2014. News.com.au understands Edwards was self-employed and had been aligned with AMP from 1995 until 2016.

”37 years of experience as a self-employed businessman,” Edwards wrote in his LinkedIn bio.

Two “quite powerful” handguns were recovered from the scene at Normanhurst.

“The 68-year-old male was the holder of a number of firearms. The two handguns were registered in his name,” Supt McFadden told reporters in Sydney on Friday.

“We understand that those handguns came into his possession lawfully earlier this year.

“The information we’ve gleaned … leads me to believe this was premeditated and planned.”

Police say they were “aware” of the father and the teenagers had been at home by themselves in the moments leading up to their deaths but that his criminal record from “many years ago” wasn’t “extensive”.

“The details about the nature of the relationship, particularly in recent times, and the level of access that the 68-year-old had to his children is subject to investigation,” Supt McFadden said.

“I do know there were some custody hearings over the last two years.

“This was a planned activity on the part of the 68-year-old male and we are of the belief that shortly thereafter he has attended the address at Normanhurst and taken his own life.

“It’s too early to get a full appreciation of what went on in the (West Pennant Hills) premises.”

Supt McFadden told news.com.au it had not yet been determined how many shots were fired but that police were speaking with several witnesses.

He told reporters the attack was a “very harrowing experience for those initial responding emergency service providers” who were called to the “horrific scene” following reports of gunshots.

“It is what can only be described as a tragic set of circumstances for the whole family,” Supt McFadden said.

NSW Ambulance Inspector Kevin McSweeney told reporters that when paramedics arrived they “were confronted with an extremely distressing and stressful situation”.

“Two teenagers were unfortunately deceased in their bedroom and unfortunately at that time there was nothing we could do to help them,” he said.

At the scene of the bloody attack on Thursday evening, forensic investigators wearing white protective suits could be seen walking up and down the street with torches and cameras.

About 150m of the road was blocked off, with witches hats stopping cars from entering one end, and uniformed police officers standing guard on both. Some residents who lived in the exclusion zone were escorted back inside their houses upon arriving late to the horror that, on this occasion, had come too close to home. It’s understood the two teens’ bodies were removed just before 6am.

Longtime resident John Howard, 82, told news.com.au it was “normally a pretty quiet street”.

Mr Howard said he didn’t hear any gunshots. He was alerted to the incident when his daughter saw it on the news and contacted him before he came outside.

“I couldn’t believe it,” he said. “It’s so horrific … especially for such young people to be the ones killed.”