Twins Stephen and Richard Mateer face sentence hearing for historical child sexual abuse

The Mateer twins, 71, on Friday afternoon appeared in court via audio visual link from jail to face a sentence hearing after the pair were found to have committed a string of sexual and indecent assaults against two young boys between 1989 and 1993.

After Stephen Mateer was found unfit to stand trial on 45 charges due to dementia, the pair had last year faced a concurrent special hearing and judge-alone trial in Newcastle District Court.

Those proceedings concluded with Judge Peter McGrath making "qualified findings of guilt" in relation to all but three of the charges against Stephen Mateer, although eight were not in the "aggravated" circumstances in which the charges were put to the court.

Richard Mateer was found guilty of all eight counts, related to the abuse of one boy.

But on Friday afternoon, when it came time for the sentence hearing, Judge McGrath was told Richard Mateer was now showing the "early signs of cognitive deterioration" and would need to be assessed by a neuropsychologist before he could be sentenced.

That meant little progress could be made on Friday, but the two men did sit and listen as one of the victims read an emotive victim impact statement.

"I was only an innocent child," the man said. "A child who hoped for a happy, fulfilled future of holidays, fun, health, education, work and family. Unfortunately for me none of those came about. Instead, by the actions of an adult, I was denied these positive aspects of life and learned pain, fear, anxiety, violence and depravity."

The court heard that Stephen Mateer preyed on two boys while they were aged between 12 and 14 in the Lake Macquarie area from the late 1980s to the early 1990s.

In one attack in the back of a van, the brothers touched the genitals of one of the boys, before inciting him to manually stimulate them. Richard Mateer then raped the child.

Judge McGrath found that Stephen Mateer sexually assaulted this boy and another on separate occasions while taking them for driving lessons.

Another time, Stephen Mateer - who met the boys through the Belmont pizza shop where he worked - incited the children to touch each other.

Stephen and Richard Mateer were arrested after detectives from Strike Force Arapaima - investigating the long-unsolved disappearances of Lake Macquarie girls Robyn Hickie and Amanda Robinson - were tipped off to a string of alleged sexual assaults against two boys in the late 1980s and early 1990s.