The horrific shooting of two teenagers at the hands of their father in Sydney has prompted calls for a review of gun laws.

Jack, 15 and Jennifer Edwards, 13, were killed in their West Pennant Hills home by their father John Edwards on Friday.

The 68-year-old took his own life shortly after the shooting.

Opposition leader Luke Foley on Sunday said the shooting murders should prompt the community to "pause and reflect" and examine what can change.

"What happened last week should cause us to examine whether there are improvements that can be made," Mr Foley told reporters in Sydney.

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He floated the idea people be alerted or have a say when their partners or ex-partners apply for a gun.

He also suggested reviewing the NSW laws surrounding gun clubs and removing guns from their premises.

Not-for-profit group Gun Control Australia has called for new family law firearm safety checks.

GCA director Samantha Lee says current gun laws fail to adequately protect women and children because they require an AVO to be in place or a charge for a criminal offence before a firearm may be revoked or suspended.

"By then, it may be too late to save a life," Ms Lee said in a statement.

The new checks would be compulsory and required to be undertaken once custody proceedings were lodged in the Family Court, GCA said in a statement.

They would include a firearm licence review where police would check if any person involved in family court proceedings had a gun licence and if there was any concern for the safety of that person, their immediate family or the public.

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Police would also notify the partner if the other party had a gun licence, made an application for a firearm licence or an application to obtain a permit to acquire a licence.

The partner would be able to object to the application or continuation of the licence if they had safety concerns.

Under the reforms, police would have the power to suspend or revoke a licence and not issue a permit.

Police say Edwards had been in a custody battle with the children's mother Olga Edwards, for two years following the breakdown of their marriage.

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Two "quite powerful" handguns registered in the father's name were used to kill the children and were found later at Edwards' Normanhurst home, along with several other guns he owned, police said.

NSW Attorney General Mark Speakman has been contacted for comment.

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