A former Adelaide teacher will serve at least six years behind bars for sexually abusing a student almost three decades ago.
Bevan Charles Wilson, 71, was found guilty in May of maintaining a sexual relationship with a child between 1994 and 1996 after a District Court trial.
Judge Jane Schammer on Wednesday sentenced Wilson to 12 years jail but set a lower non-parole period of six years given his advancing age and poor health.
Judge Schammer said Wilson was diagnosed with Parkinson's disease in 2009 and was now "physically frail".
The non-parole period has been backdated to when Wilson's bail was revoked on September 9.
Judge Schammer described the offending as incredibly serious that involved a gross breach of trust in his role as a teacher, and had an "enormous impact" on his victim, who was 13 when the offending began.
Judge Schammer said Wilson met the then year 8 student at a school where he worked, although he never taught them.
She said Wilson groomed the student and befriended their mother.
"You grossly breached the significant trust that was placed in you by them both," she said.
The survivor previously told the court in a victim impact statement that their life had been "torn to pieces" by Wilson, who they described as a "monster".
Judge Schammer said Wilson, who was arrested in 2018, had maintained his innocence and as such had not apologised to his victim "nor demonstrate any contrition or remorse for the significant trauma you have caused".
