Up until being charged and jailed for the killing of his former wife, Harmer was said to have been a "model citizen", who was a champion sheep farmer and local government manager.
At the time of the fiery car explosion on his farm, that killed Thomas, police and firefighters believed his account of trying to pull his wife, who had multiple sclerosis, from the vehicle.
But a year later he was arrested and a jury accepted Harmer had either burned his wife to death while unconscious, or killed her first and burned the body in an attempt to avoid losing his farm when they split, Fairfax reported.
The farmer was sentenced to a minimum term of 14 years for her death and became eligible for parole on August 11 this year - before being released in September.
He'd appealed his conviction to the Court of Appeal - but the murder conviction stood.
A prison psychologist who prepared a report for the parole board said Harmer's ongoing risk of violent re-offending was low.
She suggested the person at greatest risk from him would be a close, intimate, partner, in particular if that relationship was about to end.
According to Fairfax the Parole Board was satisfied that Harmer did not pose an "undue risk" to the community.
Its report described his conduct in prison as "exemplary" and he completed a diploma in agribusiness and helped other offenders with their studies.
His two daughters from his first marriage also supported him at the parole hearing.
The conditions of his release prevent him from contacting any members of Thomas' family, and is under a 10pm to 5am curfew for two months.
On a website dedicated to Harmer's innocent, his current wife, whose name had been suppressed at the trial, told of how she worked as a prostitute in Wellington in the late 1990s.
She said Harmer had tracked her down and she'd agreed to see him as a private client and their relationship developed after the death of her mother.
"Kevin was not possessive, a very gentle person, not obsessive or pushy, and (I) felt totally safe in his company," she said.
His wife also recounted how she'd received a phone call from the farmer, four days after his wife died, and remembered him as being "extremely distraught and distressed."
She's supported him through the trials and imprisonment and continued to believe his innocence.
"I have no regrets, I have told no lies, and continue to love and believe in Kevin. The tragic loss of a wife and second mum that is shared by his two daughters, has been exacerbated by this malicious action."
