The identification of the gunman behind an attempted murder was "contaminated" by "expectation bias", a court has been told.
"This is a case ... in which there is a very real risk that an innocent person has been convicted," counsel for Sugimatatihuna Bernard Gabriel Mena, 25, told a full bench of the ACT Court of Appeal on Tuesday.
Barrister Riyad El-Choufani made that claim as he challenged Mena's convictions for attempted murder, aggravated burglary and committing an act endangering life.
A jury found Mena guilty of those charges last year, concluding he had invaded the Spence home of a drug dealer in March 2021.
While inside, Mena used a sawn-off rifle to shoot the drug dealer's driver in the face and stomach.
Justice David Mossop, who subsequently jailed Mena for nearly 10 years, said the shooter had been motivated by baseless allegations about the victim being a paedophile.
Co-offenders Rebecca Dulcie Parlov and Bradley Joe Roberts, who burst into the house ahead of Mena, were both found guilty of aggravated burglary and given jail sentences.
The intruders' identities were the central issue at both of the trio's trials, the first of which ended with a hung jury.
To prove their guilt, the prosecution relied on the evidence of the victim and his drug-dealing friend.
Both of these people identified the accused trio, saying they knew them and had recognised them.
But on Tuesday, Mr El-Choufani cast doubt on the identification as he argued the evidence should not have allowed the jury to find his client was the shooter.
Mr El-Choufani referred to a conversation that had occurred, hours before the shooting, at the Bonner shops, where Roberts told the victim he was going to "get Sugi" and "come back and whack you".
He argued this had created an "expectation bias" in the victim and his friend, who later assumed the masked shooter was Mena.
Mr El-Choufani said it was possible the two key witnesses had made an honest mistake in identifying Mena, with whom they had "little familiarity".
He pointed to evidence that suggested the "extraordinarily violent interaction" had lasted only a matter of seconds, giving the victim and his friend barely any time in which to identify the shooter.
Mena's counsel went on to raise two further grounds of appeal, one of which involved claims a miscarriage of justice occurred because the judge at the second trial had given the jury inadequate directions.
Mr El-Choufani also argued the judge, Justice Mossop, made a legal error by not giving a certain direction at all.
Roberts, who is serving three years and three months in jail over his role in the home invasion, is also appealing against his conviction.
On Wednesday, barrister Mary Keaney, is set to argue, among other things, that the jury's verdict in relation to Roberts was unreasonable or could not be supported by the evidence.
Prosecutor Mike Smith will then address the appeal court, which is comprised of Chief Justice Lucy McCallum, Justice Belinda Baker and Justice Robert Bromwich.
