A MAN who fatally stabbed a Bendigo newsagent in his shop has been found not guilty by reason of mental impairment.

Antony John Duguid, 47, was a paranoid schizophrenic with a 20-year history of mental illness, who lived by his own belief system, the Victorian Supreme Court heard today.

Late on October 18, 2011 Duguid stabbed newsagent owner Garry Angus 30 times in the hand, face and neck, in the Bendigo shop he operated with his wife, the court heard.

Duguid admitted the attack the following day.

Justice Elizabeth Curtain found Duguid to be mentally impaired after psychiatric evidence found that although he was aware of what he was doing, he was not aware it was wrong.

The court heard Duguid referred to himself as Crow, and lived by the Crows Law. He wrote in detail about the beliefs.

Duguid expressed anti-homosexual beliefs and repeatedly got tested for sexually transmitted diseases, the court heard.

Both the prosecution and defence had agreed that Duguid was mentally impaired.

Duguid was remanded to the Thomas Embling Hospital until December 10 while a report on his psychiatric condition is prepared.