Robert John Hall was given a five-year sentence with one year non-parole on two counts of sexual intercourse without consent and two counts of threatening actual bodily harm with a weapon to coerce sex. Credit:Facebook Hall pushed her to her knees and made her face the wall. She heard a rustling of paper. He taped bandages over her eyes and sexually assaulted her at knife-point in two ways over the next 15 to 30 minutes. "I paid the money now you just lay back there and I can do whatever I f---ing want," he said. "If you do that again I'll f---ing kill you," he warned when she tried to turn around. He was not wearing a condom. It was her first day at the agency, March 25, 1990.

Robert John Hall was convicted of raping one sex worker and suspected of raping another. He pleaded not guilty to the charges he faced, claiming the sex was consensual. Credit:Facebook HOW A PETTY THEFT LED TO A RAPIST Hall may never have been caught had he not made a mistake. His victim, who cannot be named legally, reported the attacks immediately on that March night in 1990, first to her waiting cab driver and then to the motel receptionist. Doctors at the hospital took DNA samples from her vagina, but police closed their investigation the same year. Then, in 2007, Hall committed a petty crime, the first on his criminal record since armed robberies decades before. He drove off from a petrol station in Queensland without paying.

Queensland Police swabbed a DNA sample with his permission, and in 2010 their NSW counterparts were told of a match. The petrol thief and the Kiama rapist shared the same DNA profile, a profile to be found only once in a theoretical sample of 100 billion Australians. Police in NSW arrested Hall three years later. At trial, he testified the sex was consensual but a jury convicted him in November of two counts of threatening with a weapon to inflict bodily harm to coerce sex and two counts of sexual intercourse without consent. He was sentenced this month to a maximum term of five years' jail with one year non-parole. Hall, 59, had spent the entire proceedings on bail, including after conviction, as he wanted to visit his surgeon about a recent hip replacement. But District Court Judge Peter Whitford said Hall was already reformed before custody, even as he continues to deny the offences he committed aged 32 in the Kiama motel.

Describing the case as "highly exceptional" and "most extraordinary", Judge Whitford said it raised serious questions about the purposes of sentencing and tested the limits of judicial discretion. However, District Court registrar Nicole Hoffman refused to release redacted material Judge Whitford considered in exercising that discretion, arguing it was "almost impossible" to know what detail might tend to identify the sexual assault victim. In his remarks, Judge Whitford noted Hall's "objectively quite terrible criminal conduct", his lack of remorse and the psychological harm inflicted on the victim. On the other hand, he said the assaults took place over a "relatively short" period of time, that Hall's family had suffered greatly during the legal proceedings and Hall himself presented as a medium suicide risk. Judge Whitford paid greatest attention to the character Hall had displayed since 1990, including "exemplary devotion to his family" as a husband of 20 years and as an "idolised" father and grandfather.

He observed Hall's reputation for integrity in his earthmoving business as well as his volunteer firefighting and efforts during natural disasters. "Mr Hall has already established that he can rehabilitate himself, and indeed has," Judge Whitford found. "He has become a fully participating, productive member of society. "In addition to the demonstrable contribution he has made to the life of his family, through his voluntary work the offender has given back to society far more in the last 25 years than many ordinary citizens manage in a lifetime." SENTENCING IS 'RARELY EASY', JUDGE SAYS

While factoring in Hall's good conduct in the decades since the offence, Judge Whitford also found him entitled to receive some sentence reduction because his crimes belonged to a time when rape sentences were much lighter. (The maximum penalty for rape today is 14 years' jail and the standard non-parole period is seven years.) Hall's lawyers also argued the delay between charges and sentencing – four years – justified some reduction in jail time, which Judge Whitford accepted to a limited degree. "The task is rarely, if ever, easy," he said of sentencing. If separate sentences for each conviction had been imposed, the judge said he would have ordered terms of four years' jail for each of the weapon threat offences and three years' for each of the sexual assaults, a total of 14 years.

But he ordered the prison terms to be served largely at the same time, over a maximum of five years, as they all related to the one course of criminal conduct. A one-year non-parole term means Hall would be eligible for release on August 31, 2018. Such a sentence would be unacceptable, Judge Whitford said, had the same offences been committed in the recent past. The Office of the Director of Public Prosecutions believes the penalty is too light and has launched an appeal, which will be first heard in the Court of Criminal Appeal on September 28. Hall's lawyer, Leo Premutico, said this week he planned to file an appeal against the conviction. Do you know more? Email patrick.begley@fairfaxmedia.com.au