After an argument with a young woman inside a glamping tent, Nicholas James Cross pulled out a gun, pointed it at her forehead and pulled the trigger at point blank range.
Maddison Jane Pante was killed instantly on December 3, 2018.
The trauma of the 29-year-old's horror murder didn't end there for he family and friends.
In an effort to cover his tracks, Cross or another at his request returned to the tent and set it alight with Ms Pante's body inside.
The 35-year-old was jailed on Friday for 27 years for his actions on December 3, 2018.
He must serve at least 21 years before he's eligible for parole.
Ms Pante's family and friends, including her parents Marlene and Dale Parrott, packed the small Geelong courtroom for the sentencing by Supreme Court Justice Rita Incerti.
There were claps and cries of "yes" as the sentence was handed down.
Wearing a white T-shirt, Cross looked at his hands throughout the hearing.
Cross maintains his innocence, his lawyer Glenn Casement told a pre-sentence hearing in December.
He had said it was not an aggravating feature of the crime that Cross blames another person for Ms Pante's murder, but noted it supported the point that his client was "utterly remorseless".
Cross was found guilty of murder by Justice Incerti after a three-week judge-alone trial.
She said his decision to shoot Ms Pante was spontaneous and impulsive in circumstances where she was unarmed and not acting aggressively.
"You shot her in the heat of the moment and with no warning. You thoughtlessly acted in the most violent and deadly way," she said.
"This was an utterly senseless killing ... unprovoked (and) cold-blooded."
Mr Casement had tried to argue that it was a sign of remorse that Cross had turned to Ms Pante's boyfriend immediately after killing her and apologised for what he had done.
Justice Incerti said she didn't accept his uttering the word "sorry" as remorse.
Right up until Friday he had said or done nothing to indicate his remorse or regret for his ghastly actions, she said.
Prosecutor David Glynn previously made the same point.
"The apology was ... in the sense of 'sorry I just killed your girlfriend', which is a bit different to anything actually approaching remorse," he said.
