A doctor who took a selfie with his wife moments before bludgeoning her to death wrongly believed she was having an affair with his close friend.
63-year-old Robin Michael posed for a photo with wife Kerry, 44, while climbing Mt Roland in northwest Tasmania during a holiday in February 2015.
A coronial inquest, released on Thursday, found Michael launched a 'brutal, vicious and sustained' attack on his wife, shattering her skull.
It was then, he wrote a confession to Facebook, saying he couldn't understand his own actions.
Micahel's drafted a suicide note and letter of confession to his children before attempting to kill himself later that night.
Police were able to reach him in time after a friend spotted his disturbing social media post and alerted authorities, who raced him to hospital under guard.
'I have committed an act which should attract no pity, no sympathy, not even any understanding. I can't understand it,' Michael wrote hours after murdering his wife.
'That it was an effect, rather than a cause, bears no consequence. It was not appropriate, necessary, nor anything really other than pure evil.'
'The English language cannot describe my anger and rage. I cannot contemplate it,' the post continued. 'In the heat of the anger with Kerry's admission I had no control or influence over myself.'
Michael's, the former general manager of Royal Darwin Hospital, accused his wife of having an affair with one of his closest friends. This claim has been dismissed by coroner Simon Cooper in his findings.
Michael's was found dead in his Hobert jail cell.
He had pleaded not guilty to murder, despite telling police what had occurred on the day of the attack, News.com.au reported
For those seeking support or information on suicide prevention please contact Lifeline on 13 11 13 or visit beyondblue.com.