IN A horrendous case of sexual abuse, a father molested his son every fortnight, including once at the Longford caravan park, over a period of five years.
The man, a church volunteer who cannot be identified, was charged with maintaining a sexual relationship with his son more than three decades ago.
The man pleaded guilty but disputed large parts of the Crown case that led to a hearing in the Supreme Court last year.
In a decision published on Friday, Justice Helen Wood sided with the victim's evidence, identifying 11 specific sexual assaults.
``As a conservative estimate, the background for the 11 incidents is that during a period of nearly five years, the defendant abused his son approximately once a fortnight,'' she said.
The abuse started when the son was eight and lasted until he was 13 or 14.
It happened on the son's weekend visits with his father, who had separated from the child's mother.
The abuse would take place when the father's partner and later wife was out of the home.
It stopped when the victim confronted his father, who warned him not to report it or he would never see him again.
`` The complainant loved his father and so did not complain,'' Justice Wood said.
The conduct was a ``grave betrayal of his son's love and trust''.
The abuse was highly degrading, including anal rape, the court heard.
Justice Wood said the offender tried to minimise his wrongdoing and even blamed his son, telling police in 2012 that the child had instigated it.
He sought to undermine his son's reliability, saying that he had had memory problems since a motorbike accident.
Justice Wood said the abuse was devastating on the son, who suffered tormenting memories and had made attempts to end his own life.
``He has struggled for most of his adult life with a debilitating sense of worthlessness and lack of confidence,'' she said.
Despite this, the son was now trying to live his life in a positive fashion, and it appeared the court case was offering him some resolution, she said.
Justice Wood said the victim's mother has also suffered enormously.
``She is grief-stricken by the thought that her son has been robbed of a happy childhood, and all that her son has suffered,'' Justice Wood said.
She noted that the man had not offended in three decades and had contributed to his community.
``He has had a volunteer role with his church in its pastoral work,'' she said.
The man was sentenced to 7.5 years' jail with a non-parole period of four years.
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