Newson, now 46, was on June 24, 2021, convicted of murdering mother-of-two Carly McBride, a jury left with no doubt he intercepted the 31-year-old after she left a visit with her daughter at Muswellbrook on September 30, 2014, and inflicted a number of blows to her head and back before dumping her body near the side of a road outside Scone.

Four days later - after news of the guilty verdict had been widely publicised - Newson was in his cell in F block about 8.50am when three inmates, including Christopher Dale Williams and Denham Hedges, entered intending to "stand over" or intimidate him.

That was the plan, according to police, but once the three were inside Newson's cell, the convicted killer was attacked and assaulted.

About 40 seconds later, when the cell door burst open and the group spilled out, Newson was bleeding from injuries to his face and the third inmate - who police allege was Richard Exton - was lashing out at him with a kettle.

The rest of the altercation was captured on CCTV inside the jail, with Newson and the third inmate both "shaping up" and yelling at each other.

At one point, the third inmate and Williams backed Newson up into a doorway at the end of the landing and as Newson punched out and attempted to protect his face, the third inmate repeatedly punched Newson, holding him by his shirt and striking him in the head and body as Newson attempted to get away.

Newson then fell to the ground as the third inmate continued to try to punch him. Eventually, Newson got up and managed to get away.

Another inmate intervened and corrective services officers arrived to find Newson and the third inmate yelling at each other and Newson bleeding from injuries to his face.

Newson was taken to Maitland hospital and then transferred to John Hunter Hospital to treat several facial fractures, including two that needed surgery and one that required a metal plate.

Newson refused to give a statement or give an interview to police, but after watching the CCTV footage police charged Williams, Hedges and Exton.

Williams, who has since been released from jail, appeared in Newcastle Local Court on Wednesday where he pleaded guilty to assault occasioning actual bodily harm in company after prosecutors withdrew more serious charges of reckless wounding in company and reckless grievous bodily harm in company. Hedges had pleaded guilty to the same charge in Newcastle Local Court last week and both men will be sentenced in July.

Exton has not entered any pleas to four serious charges and will next appear in Lismore Local Court on June 14.

The Herald reported last week that Newson had lodged an appeal against his conviction and sentence.