A pensioner who repeatedly raped an autistic boy at a Launceston shelter will have to serve at least four years of a six-year prison sentence.
The 52-year-old, who can't be named, pleaded guilty to persistent sexual abuse of the then 13-year-old, after the victim and his mother had moved into the temporary accommodation.
The court heard the child now displays inappropriate sexual behaviour, including public masturbation.
"His life skills and level of independence have generally regressed," said Justice Robert Pearce in sentencing.
"His eating and sleeping routines have changed, he has aggressive outbursts, his level of hygiene has deteriorated, and he has withdrawn from his grandfather and the other male family members.
"Some improvement has occurred as a result of respite at a specialist retreat where he is assisted by therapists and psychologists."
The predator will go on the sex offenders register for 10 years after he's released.