Members of the RAAF, ambulance, fire and emergency services gathered with local law enforcement at the grave site of fallen Katherine policeman Constable William Condon.

This year marked 30 years of the national remembrance day where police officers across Australia pause to pay tribute to colleagues who have died.

"In every corner of the Territory police are out there making sacrifices and keeping people safe," acting Commander Peter Kennon said in a welcome speech.

"In policing there is no compensation great enough to make up for the horrors of trauma faced and the individual sacrifice.

"It is also a day of celebration, celebrating the lives of our colleagues and celebrating the bond we share... It is a celebration of the commitment we share and the service to our community."

After May Rosas' Welcome to Country, readings, and a poem read by Constable First Class Jackson Kruse, Julie Howard from the Salvation Army thanked police on behalf of the community.

"Today we are gathered here to remember all police officers who have put their lives at risk on the line of duty," she said.

"Someone needs to stand in the gap... someone needs to put their bodies between the victims and those who do evil.

"The Websters dictionary defines 'to stand in the gap' as to expose one's self for the protection of something, to make defense against any assailing danger, to take the place of a fallen defender or supporter.

"And that is what our law enforcers do every day."

In a moving tribute to police officers she said they are the reason the community can sleep with confidence each night.

"You do the work we cannot do... with the courage we don't posses, you stand in the gap and for that we are thankful," Mrs Howard said.

"You deal with the worst of our citizens in the worst of situations... day in day out, week after week, year after year for too little pay and not enough recognition."

Wreaths were laid on the grave of Constable William Condon, by members of the community, including Mayor Fay Miller, St John Ambulance area manager Ashlee Elton, and Acting Commander Peter Kennon on behalf of the NT Police Force.

On June 9, 1952, Constable Condon was in Katherine from his usual station of Maranboy, assisting with the Katherine Races, when he was called upon to search for an armed gunman, 23 year-old Terence Stapleton.

About 7.25pm the 29 year-old police officer, married for only 12 months, observed Mr Stapleton in the main street of Katherine.

Without hesitation he approached Mr Stapleton with hands open to show he was unarmed.

But Mr Stapleton produced a firearm and fired twice, killing the young constable.

Constable Condon was posthumously awarded the Queen's Police Medal for Gallantry and a plaque was erected at Katherine police station.

Services were held across the Territory in Darwin, Tennant Creek, Alice Springs, and Nhulunbuy today.

Acting Commissioner of Police Michael Murphy APM said this year's National Police Remembrance Day was particularly important in light of the lives lost to illness or other tragic events in the past 12 months.

"This is an important day as we have felt first-hand the loss of our own officers which hits our police family hard and is felt like a ripple affect across the region." said Acting Commissioner Michael Murphy

"Every day our members don their uniform and actively go out to protect the community, enforce laws which are essential to living in harmony and run towards the chaos rather than away from it."

"This is our job, our role within the town and our chosen profession, but we ask the community that for one day they unite and stand with us."

"Tomorrow we stand united across Australia and take a moment, to reflect, to honour and to pay tribute to those who have died in the line of duty or died whilst on duty."

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