The courts have thrown out appeals in the case of a street preacher who rendered another man a tetraplegic in a frenzied knife attack.
The ACT Court of Appeal upheld on Thursday the conviction and nine-year jail term imposed by acting Justice Jane Matthews on Isa Islam in 2010.
Islam, 40, who represented himself in the appeal against his conviction and sentence, argued he was mentally impaired at the time of the offence.
The court also dismissed a cross-appeal by the Director of Public Prosecutions, which sought to increase Islam's sentence.
Islam was convicted of attacking Andrew Dyer at a northside takeaway in July 2009.
During the frenzied attack, Islam stabbed Mr Dyer with a paring knife until the blade broke.
The knife hit Mr Dyer's spinal column, leaving the victim paralysed down one side of his body and reliant on a wheelchair.
The two men had been neighbours at the Ainslie Village supported accommodation, and Islam had believed Mr Dyer had been stealing from him.
Islam was acquitted of attempted murder but found guilty of a lesser charge of inflicting grievous bodily harm after a trial in 2010.
He was subsequently sentenced to a nine-year jail term, with a non-parole period of four years.
At last year's appeal hearing, Islam argued the trial judge failed to use the "balance of probabilities" test to decide if he suffered a mental impairment at the time of the attack.
He said a neuro-psychological test and his "illogical" behaviour after the stabbing, when he tried to render first aid to Mr Dyer and stayed until police arrived, was evidence of the impairment.
In the cross-appeal, Director of Public Prosecutions Jon White argued that the non-parole period was inadequate.
Mr White told the court the non-parole period, which was 50 per cent of the total sentence, should also have been a greater proportion of the total sentence.
Justice Richard Refshauge announced the court's decision on Thursday, and will publish his reasons later.