A street preacher responsible for a frenzied stabbing that left another man wheelchair-bound has told a court he was mentally impaired at the time of the offence.
Isa Islam, 39, also told the ACT Court of Appeal he was deeply remorseful for his actions and wanted to financially support his victim when he was able to earn money.
Islam repeatedly stabbed short-order cook Andrew Dyer outside a takeaway shop in Ainslie in 2008, leaving the man a quadriplegic.
The two men had been neighbours at the Ainslie Village supported accommodation and Islam believed Mr Dyer was trying to persecute him.
After a trial in 2010, Islam was acquitted of attempted murder but found guilty of a lesser charge of inflicting grievous bodily harm.
He is serving a nine-year jail term with a non-parole period of 4½ years.
Yesterday the Court of Appeal heard appeals by both Islam and the Director of Public Prosecutions.
Islam represented himself in an appeal against his conviction and sentence.
But the DPP cross-appealed, arguing Islam's sentence was too lenient.
Islam told the court that the trial judge, Acting Justice Jane Matthews, failed to use the ''balance of probabilities'' test to decide if he suffered a mental impairment at the time of the attack.
He pointed to 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, as evidence of the impairment.
Islam was told that even if Acting Justice Matthews found him to be mentally impaired, she could still have decided the impairment was not so great that he could not control his behaviour.
Islam said he had written to Mr Dyer and his family, apologising for his actions and telling them that if he was ever in a financially secure position he would offer Mr Dyer compensation to help pay for his care.
In the cross-appeal, Director of Public Prosecutions Jon White told the court that the 4½ year non-parole period imposed by Acting Justice Matthews was inadequate.
He said the non-parole period, which was 50 per cent of the total sentence, could also have been a greater proportion of the total sentence.
But defence barrister Ken Archer, who represented Islam in the cross-appeal [Islam was self-represented in his own appeal], said community protection didn't require Islam to serve a longer non-parole period.
He said while Mr Dyer's serious injuries were an important part of the considerations for sentence, Acting Justice Matthews had also taken into account other factors, such as the unplanned nature of the stabbing.
Mr Archer said the judge had structured the sentence to ensure Islam's underlying issues, which included psychotic behaviour possibly brought on by drug use, could be addressed.