An inmate who carved an Islamic State-inspired message on his cellmate's forehead sent a letter to the Corrective Services Commissioner boasting that he turned the man into an "Islamic State sketch pad", a court has heard.

Key points: Hraichie carved "e4e" — a reference to "an eye for an eye" — into a cellmate's forehead

Hraichie carved "e4e" — a reference to "an eye for an eye" — into a cellmate's forehead In a letter threatening the Corrective Services Commissioner, Hraichie claims his attack on Michael O'Keefe was "Islamic State-inspired"

In a letter threatening the Corrective Services Commissioner, Hraichie claims his attack on Michael O'Keefe was "Islamic State-inspired" The prosecution says he has not shown remorse

Bourhan Hraichie, 21, faced a sentencing hearing before the NSW Supreme Court over a series of offences — including the attack on the inmate — as well as plans in October 2015 to shoot police on the steps of Bankstown police station and to film the attack.

He pleaded guilty to four charges, including doing an act in preparation for a terrorist act, causing grievous bodily harm and wounding with intent to murder.

At the time of the alleged offences he was 18 and 19.

The court heard while Hraichie was serving time at Kempsey jail in 2016, he carved 'e4e' — a reference to 'an eye for an eye' — into cellmate Michael O'Keefe's forehead.

Michael O'Keefe's injuries are permanent. ( Supplied )

O'Keefe's injuries are permanent and "the victim will carry the scarring on his face and back of his neck for the rest of his life," court documents revealed.

In a letter threatening the Corrective Services Commissioner, Hraichie said his attack on O'Keefe, who claimed to have been a soldier, was "Islamic State-inspired" and that he had "turned your soldier into an Islamic State sketch pad".

In the letter, Hraichie threatened to "turn your jails into slaughterhouses", Commonwealth prosecutor Sophie Callan told the court.

The court heard that in 2016 Hraichie obtained firearms and knives to use against Bankstown police because of their involvement in counter-terrorism investigations.

He also praised the man behind the murder of police accountant Curtis Cheng.

During the sentencing submissions, Hraichie did not stand when the judge entered the court.

"Will that be the case through the hearing?" Justice Peter Johnson asked his barrister Gabrielle Bashir SC.

"I hope not," she replied.

Documents tendered to the court included details from a police interview at Goulburn on September 14, 2016.

However, Justice Johnson suppressed the video and transcript of the interview because he did not want it to be "misused by others, including those who are promoters of violent jihad and others with a fixated view".

Hraichie threatened to "personally execute" NSW Corrective Services Commissioner Peter Severin. ( ABC News )

Ms Callan said Hraichie's admissions to Federal Police did not show remorse or contrition.

Judge Peter Johnson asked whether it was submitted that Hraichie's admissions were a "type of boasting?".

"Yes, he is asserting in a proud way what he's planned," Ms Callan replied.

She said Hraichie had done considerable planning that was "not dissimilar to the violence that resulted in the killing of police accountant Curtis Cheng".

Hraichie intended the plan to be a terrorist attack and was determined to see the plan through — even though he was in custody, Ms Callan told the court.

"He wanted to be the face of the attack" by recording himself and disseminating it to the public, she said.