The mother told the Otago Daily Times there were never any warning signs about Clemenger’s conduct.
“He’s so good at getting on with people,” she said.
She described the work Clemenger had done in prison as “tick-box courses” and doubted he would change, given such a long-standing sexual attraction to children.
The offender told a psychologist his depraved tendencies had emerged at 10 years old and he started viewing pornography a year later.
His predilections were uncovered by his own family in 2006, which led to some counselling and short periods of abstinence.
In 2009, Clemenger was implicated in an investigation by the Department of Internal Affairs and charged with downloading objectionable material.
But he was granted diversion on the proviso he undertake treatment.