On July 9, 1995, the two Kempsey-based police officers were called to Crescent Head at 12.35am to investigate a domestic violence report.

They arrived to the address on Walker St at around 1am and found themselves under fire from a drunken gunman hiding near a carport.

The gunman, John McGowan, was dressed in camouflage and was in possession of a high-powered rifle.

Addison and Spears, both aged 36 at the time, returned fire as they sought cover behind their police car.

As Addison tried to call for back-up at 1.22am, Spears, a policeman of eight years, was fatally wounded.

As a desperate bid to find help for his wounded friend and colleague, Addison ran to a nearby house to use the phone to call for help, but the house did not have a landline.

Addison, a 14-year veteran, then attempted to run to a second home nearby, but was shot dead by the gunman.

Their murderer then turned the gun on himself, taking his own life.

A month after their deaths, in August 1995, the pair were awarded the Police Force's highest honour, the Commissioner's Valour Award.

On this significant day, Mid North Coast Commander, Acting Superintendent Paul Fuller, will lay a wreath at the Crescent Head memorial plaque - in honour of the fallen officers.

"Today, we at the Mid North Coast Police District remember two courageous and brave colleagues," he said.

"They confronted the fear and danger to protect their community. They made the ultimate sacrifice, and we will never forget what they did that Sunday in July 1995.

"Their bravery and professionalism lives on through all their colleagues and the officers who came after them. They are a true example of the courage every NSW Police officer displays every day," Acting Supt Fuller said.

The families of both Addison and Spears would go on to forever be tied together, not only in their loss, but with the marriage of their children Glenn Addison and Jade Spears, who were 16 and 15 at the time of their fathers' deaths.

In 2015, on the 20th anniversary of the tragic day, the then NSW Police Commissioner Andrew Scipione led a memorial service in front of serving and former police officers, family and friends of the fallen officers and members of the Crescent Head community.

Mr Scipione also presented Senior Constable Addison's widow, Liana, and Senior Constable Spears' widow, Kathy, with National Police Service medals in recognition of their late husbands' diligence to duty.

"Senior Constables, Peter Addison and Robert Spears, walked into an ambush," Mr Scipione said at the memorial in 2015.

"Human instinct would demand you remove yourself from harm's way in a situation like that, but not these brave officers," he added.

"They knew they had to try to stop this gunman who could have gone on to kill or injure others.

"They stood their ground, defending themselves and their community from a cowardly assassin.

"Peter Addison was not prepared to leave his wounded friend and colleague. Together they made the ultimate sacrifice and we will never forget them for it."

The deaths of Addison and Spears led to major reforms to frontline policing in the NSW Police Force, including the transition from revolvers to automatic pistols; ballistic vests; better radio communications and improved tactical training.

Senior Constables Peter Addison and Robert Spears will forever be remembered by their family and friends, officers who worked alongside them and the Crescent Head community. Today, and always.