Humiliated by his wife's new relationship and frustrated with a $600,000 rejected settlement, an enraged Klaus Dieter shot the woman dead after cutting off her car at a Hobart intersection in busy daytime traffic.
A jury took just two hours to find the 74-year-old guilty of murdering Olga Neubert,37, after a six-day trial in the Tasmanian Supreme Court.
They accepted prosecution evidence the German-born man knew the result of repeatedly firing a sawn-off rifle into Olga Neubert's Peugeot hatchback in May 2015.
The fatal shot came when he rested the barrel against her skull and pulled the trigger.
Defence barrister Todd Kovacic said his client had shortened the firearm and was carrying it in his car with the intention of harming himself, upset over the couple's marriage breakdown.
"He never at any stage ... wished her harm," Mr Kovacic told the jury.
But prosecutor Daryl Coates SC said Neubert was in a rage the day he used his Mercedes four-wheel drive to cut off his wife's car at an intersection, before firing at least five shots.
"Even if he didn't intend to kill his wife, he knew or ought to have known that firing a rifle into a small car was likely to kill her and was likely to cause injury to anybody in the car," Mr Coates said.
One of the shots injured a female passenger in the Peugeot, and Neubert was also found guilty of grievous bodily harm.
She lost two fingers.
Ms Neubert, 37, started seeing another man in 2014 and had since launched family court proceedings against her husband.
He was humiliated by his wife's new relationship, frustrated with the financial separation - which included her rejection of a $600,000 settlement - and annoyed at Ms Neubert's refusal to see or speak with him, Mr Coates said.
"That shows a man clearly enraged with his wife and shows why he did what he did," the prosecutor said.
German-born Neubert moved to Australia in the early 1990s and met his wife in the Philippines before the newlyweds settled near Hobart.
Neubert is due to be sentenced by Justice Michael Brett on February 24.
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