The man who supplied the gun used to kill police accountant Curtis Cheng has refused to stand for a judge while learning he would spend at least the next 13 years behind bars.

Key points: Talal Alameddine supplied a pistol Farhad Mohammad, the man who killed Curtis Cheng

Talal Alameddine supplied a pistol Farhad Mohammad, the man who killed Curtis Cheng He refused to stand in court when sentenced

He refused to stand in court when sentenced He will be eligible for parole in 2029

Talal Alameddine, 25, pleaded guilty last year to supplying a pistol to someone unauthorised to possess it and recklessly possessing a thing connected with terrorism.

When Justice Peter Johnson was about to read out the sentence he asked Alameddine to stand but he refused.

One of Alameddine's many supporters in the court stormed out of court, saying "f***ing dog".

Alameddine waved and blew kisses to his supporters as he was led from the court room by Corrective Services officers.

Mr Cheng was shot dead outside Parramatta police headquarters in October 2015, by schoolboy Farhad Mohammad, who was then shot and killed by a special constable.

Less than two hours earlier Alameddine supplied a loaded Smith and Wesson revolver to a man named Raban Alou, who then gave it to the teenager at a Parramatta mosque.

Parramatta shooting victim Curtis Cheng (L), and his family. ( Supplied: NSW Police )

Earlier in court Justice Johnson said Alameddine's offending was very serious because he was "ready, willing and able" to provide a weapon for a terrorist act.

"I am well satisfied that during protracted conversations [with Alou] at various locations the offender learned a good deal about what was to happen to with the revolver," Justice Johnson told the court.

"If the offender had refused to supply the revolver to Alou then the terrorist attack could not have taken place on that day."

Even though Alameddine's lawyers told the court their client did not hold radicalised views, the judge found otherwise.

"I do not accept that he has never held views sympathetic to Islamic State," Justice Johnson said.

"[Alameddine had] a strong inkling, at least from his conversations [with Alou], that the loaded pistol was to be used soon thereafter in a violent attack in Sydney for terrorist purposes."

The court was told the revolver Alameddine provided for Mr Cheng's murder was not licensed in Australia and police were unable to find record of it being imported legally.

Alameddine was subject to a firearms prohibition order when he supplied the gun to Alou, and the Crown was able to show evidence that he was also in possession of a gun in the days after the shooting.

Friends and relatives submitted references to the court on behalf of Alameddine, speaking of his good character and feelings of remorse, however the judge said he was not persuaded there had been any demonstration of contrition or remorse.

Justice Johnson gave Alameddine a 15 per cent discount on his sentence for his guilty pleas.

He will be eligible for parole in August 2029.