New South Wales Police is planning to crackdown on firearm regulations to stop guns from getting into the wrong hands.

As part of the overhaul, the firearms registry would be provided with details about a license applicant's mental health condition and any family law proceedings they are part of.

The proposed changes come after licensed firearm owner John Edwards shot dead his two children and then himself in Sydney on July 8.

High-powered military weapons on display as the New South Wales Government announce a state gun amnesty in Sydney last year. (AAP)

An assortment of hand guns and rifles handed in during the Federal Government. (AAP)

John Edwards entered the West Pennant Hills home of ex-wife Olga, opening fire and killing his 15-year-old son Jack and 13-year-old daughter Jennifer in their bedrooms before turning the gun on himself in his Normanhurst home.