The notorious pair evaded authorities for eight years and shot at officers during a dramatic 12-day chase across NSW and Victoria.

The pursuit ended when they were arrested on Pinevale, a remote property at Elong Elong in Dunedoo, 45 kilometres east of Dubbo, in October 29, 2015.

The badly decomposed body of Rosario Cimone, 68, the caretaker of the property, was found after their arrest.

Dramatic dashcam footage played at a sentencing hearing in the NSW Supreme Court on Friday showed the moment the Stoccos fired at police during a pursuit near Wagga Wagga on October 16, sending plumes of dust into the air.

"Urgent! Urgent! Urgent! Shots are fired! Shots are fired!" an officer yells as his car hastily reverses away from the Stoccos.

About five minutes later, the pair shot at Senior Constable Matthew Shaw during another pursuit. He also reversed away before pursuing them for a further 40 minutes.

He told the court on Friday he couldn't forgive himself for losing the Stoccos during the pursuit and allowing them to then potentially harm others.

"It took a long time to get over what happened," he said in a victim impact statement.

Mr Cimone's children also gave a victim impact statement and wept as they described their ongoing nightmares and flashbacks about the way their father, a "gentle giant", was killed.

The family, from western Sydney, had reported him missing three weeks earlier.

Mr Cimone had well-known Mafia links and the Pinevale property was being used to cultivate marijuana.

"The state of his body was so extremely ... decomposed we were unable to identify him," daughter Maria Perre told the court on Friday.

"We would never even have the opportunity to see our dad the last time and say goodbye, to tell him that we loved him and to share with him all the things we wanted to share with him but hadn't."

Her sister, Vincenza Nasso, sat beside her weeping and her brother, Phillip Cimone, stood behind the women staring at the Stoccos before mouthing "dogs" and saying "this will never be forgotten".

The court heard that the Stoccos' probable motivation for killing Mr Cimone was frustration and anger at being told to leave the property, an extremely remote and rugged plot.

The pair had worked as farm hands for a short period in September 2015 and were angry because they had nowhere else to go at a time when police were closing in on them, the court heard.

They also claimed Mr Cimone made some threats towards them and had a gun.

Prosecutor Wayne Creasey, SC, said the pair shot Mr Cimone on October 7 then stole the boots off his feet and a small amount of money on him before taking various items from his home to "give the appearance that he just left the property and was a missing person".

It's possible that others working on the site may not have reported anything to police because of the nature of the property's function, he said.

As Gino held a gun at Mr Cimone, he suggested to his son that they only tie him up however Mark was "the dominant partner" and insisted on killing him, the court heard.

Mr Creasey said it was hard to explain why the pair turned fugitives and descended into a period of "lawlessness".

They had a relatively small criminal record, had no mental health issues and no alcohol or drug use.

"They appeared to have lost their moral compass from being on the run for what were originally minor offences," Judge David Davies said.

Gino Stocco later told a doctor their behaviour "snowballed out of control".

At the height of their run from police, they returned to Pinevale in an attempt to hide but were found by police after a member of the public saw their ute in the nearby Goonoo State Forest.

It was only after their arrest on October 29, 2015, that police found the badly decomposed body of Mr Cimone.

The Stoccos built a sinister yet bizarre reputation as they ran amok through rural areas along the country's east coast for eight years.

They carried out moonlight raids to steal goods, went on vandalism sprees, stank "like a pair of polecats" and lived off the grid with no phones, licences, bank accounts or friends.

They pleaded guilty last year to murder, destroying a farmer's shed and belongings by fire in 2014 and two counts of shooting to evade arrest.

The pair pleaded guilty to several offences last year and will be sentenced in March.