A MAN who pleaded not guilty to dozens of charges of indecent assault and child sexual assault - whose alleged offences were uncovered by detectives investigating the high profile disappearances of girls who went missing at Lake Macquarie in the 1970s - has been ruled unfit to stand trial.
Newcastle District Court heard on Friday that Stephen Mateer was found to have significant degenerative cognitive impairment - likely dementia.
The court heard that, when screened, Mr Mateer's memory retention and speed was in the "extremely low range" and he displayed a lack of awareness and insight. He was unable to describe recent meetings with his solicitor or details of accusations levelled against him and did not have the capacity to make informed decisions about his defence.
Stephen Mateer and his twin brother, Richard Mateer, were each charged with historical child sex counts when detectives from Strike Force Arapaima, who were investigating the disappearances of several Hunter girls including Robyn Hickie and Amanda Robinson, were told of the alleged abuse of two boys in the 1980s and 1990s.
Stephen Mateer last year pleaded not guilty to 45 counts, including multiple charges of sexual assault, aggravated indecent assault and indecent assault against two boys.
Richard Mateer has pleaded not guilty to eight charges, including sexual assault and indecent assault in company in relation to one of the boys.
They remain in custody and will face court again on February 20. Stephen will be subject to a two week special hearing and Richard will face trial - both judge-alone matters.
