A reign of terror behind bars by the deranged female prisoner jailed for beheading her own mother has been described in court - as a judge agreed to quash the sentence of the one woman inmate who fought back.

Jessica Camilleri - who used seven knives to hack off mum Rita's head in 100 cuts and place it on the neighbourhood footpath in 2019 - has since been terrorising inmates and prison staff alike in a series of sudden, explosive attacks.

But when one prisoner fought back after a near 'scalping' by Camilleri in a women's prison, she was sentenced for assault - which a judge moved to reverse on Thursday.

In what Judge Guy Newton SC himself admitted was unusual, he said he totally believed every word of inmate LV's account of the extreme fear caused by Camilleri before and after her surprise attack in Dillwynia women's prison last year.

Despite the fact LV - who cannot be named for legal reasons - is serving time for drug and dishonesty offences, His Honour said that 'her evidence impresses me as very candid' and he did not believe Camilleri's version of events. 

The incidents of February 15, 2025, in Dillwynia's U-Bloc protection wing caught on jail CCTV show Camilleri at about 11.30am violently grabbing LV's hair and scalp from behind, then LV chasing Camilleri and eventually landing some blows.

LV was convicted of common assault and sentenced to a further one month's imprisonment on top of her four-year-plus sentence.

The CCTV has no sound, but Judge Newton said that even without audio it was plain that 'the circumstances are quite extreme'.

'The way the inmates are banging on the door, the sense of urgency in terms of their own fears [when] all the officers are at lunch at 11 in the morning,' he said.

The court heard that LV retaliated after Camilleri tried to rip her hair off because, in her words, 'I feared for myself and feared for the girls out there'.

She ran after Camilleri, kicking at her and lashing out because she believed 'I have to finish this. The guards aren't coming.'

Before quashing LV's sentence, Judge Newton described at Penrith District Court the circumstances of Camilleri's initial attack on LV that led to the payback assault.

LV had been 'sitting in an area of the prison minding her own business, playing bingo with other inmates' when Camilleri came into view behind her.

'She positions herself behind [LV] and completely without warning violently attacks her from behind grabbing her hair and pulling it with great force,' he said.

'Other inmates intervene and the two of them are separated. [Camilleri] then exits to a different part of the jail and at various times [LV] comes in further contact with her at times with [others trying] to keep the two apart.

'I found her evidence, generally speaking, cogent, redolent of a person who was being candid in terms of motivation to protect themselves and others.'

The judge said that LV and the other female inmates were 'well aware of the history' of Camilleri as a person who was 'potentially very dangerous'.

He rejected Camilleri's account of her motivation for the scalping attack, which LV's lawyer Mark Davis said had been 'a cock-and-bull story about a conspiracy between [LV] and the jail... [that] she is running... a gang, a syndicate leader, some sort of yard boss'.

The Penrith court previously heard that Camilleri routinely attacks female prison officers and other inmates, tearing out their hair and leaving wounds and bald patches, and that she threatens to do to them 'what I did to my mother'.

This created a climate of fear across the NSW prison system - among female staff and prisoners alike - wherever Camilleri is placed.

On the day in question, Camilleri had been let out of a psych ward to 'reintegrate' with other prisoners in general population.

Although the now 31-year-old convicted killer is known to strike without warning, she was apparently not under close supervision and able to plot her assault on LV.

She has since been convicted of assault after 'fixating on her dark hair and trying to scalp her', LV's lawyer claimed.

And even when other female prisoners tried to intervene and prevent LV's revenge attack, one of those trying to protect Camilleri was herself then turned upon.

Camilleri swung around and grabbed the hair of the inmate - a convicted baby killer whose identity is legally suppressed - and yanked down hard causing pain and injury to the woman. 

In court earlier this year, Camilleri had made several extraordinary claims about her life behind bars and her motivation to attack.

In one bizarre moment, she declared that 'everyone knows who... Jessica Camilleri is', adding: 'From the beginning of my sentence, when I told them what I'd done, the girls said, "Anyone who chopped her mother's head off deserves to rot."'

About the 'scalping' attack on LV, Camilleri told Penrith Local Court in February that she believed a group of seven female inmates was conspiring to portray her as 'crazy' so she would be transferred to a psychiatric hospital.

She also expressed concern that she would end up like 'Katherine Knight, never to be released'. Knight is serving a full life sentence for murdering her partner, skinning his body and cooking up body parts to eat.

'All the other girls I was physically fighting against were a long time trying to set me up so I could retaliate,' said Camilleri, who was dressed in prison greens with her hair drawn up in a bun. 

'The girls baited me... because they wanted to convince the society I was crazy. [They] wanted to convince the world I'm completely unstable.

'The fight happened over something that was a planned set-up... so I could go to Long Bay Hospital, to use psychotic treatment on me so I could never get out of jail.'

Camilleri, who has lost a significant amount of weight during her incarceration, grabbed LV's hair and yanked it back sharply, with the older woman partly saved from greater injury because her chair collapsed beneath her as she fell to the ground.

LV then retaliated, kicking and hitting Camilleri as other inmates tried to break the two up. Finally, LV grabbed a milk crate and began attacking Camilleri with it.

The large group of women prisoners on the scene then screamed 'guards! guards!' but it took officers 10 minutes to arrive.

LV said she was just playing the game when she felt her hair pulled. 'I was sitting there playing bingo, I didn't expect to be scalped, pulled down by her full weight. The girls picked up my hair and said, "Oh, my God - she's trying to scalp you."'

LV's lawyer Mr Davis has criticised prison authorities after he said officers had not been supervising Camilleri.

'To leave a psychotic woman with a proclivity to attacking prisoners and to attacking staff... was inviting bloodshed and mayhem,' he said.

It comes after the Daily Mail revealed that Camilleri - who decapitated her mother Rita on the night of July 20, 2019, after a fight over a Red Rooster takeaway order - was bragging about her ghastly crime to intimidate other women behind bars, and had even threatened to behead fellow prisoners just like she did her mother. 

Camilleri pleaded guilty to assault occasioning actual bodily harm against LV and received a one-year sentence which will be added to the end of her current sentence for killing her mother. 

She is serving 16 years for the manslaughter of her mother, after being found not guilty of murder by reason of mental impairment. 

This means she will be due for parole in December 2033.

Camilleri was also found guilty of assaulting a second female inmate who had tried to intervene when LV was charging back at Camilleri in Dillwynia prison. 

At the end of the video of the payback attack, Camilleri could be seen turning on the second inmate - a convicted baby killer whose identity is legally suppressed - and assaulting her. 

Judge Guy Newton remarked that this was extraordinary and an example of the fear among women prisoners that Camilleri could create.

Camilleri has attacked women behind bars multiple times since entering custody and has been charged with ripping chunks of hair from officers' scalps. 

Graphic videos of the attacks, which left the victims with bald patches and psychological scars, were previously shown in court.