A prisoner who savagely beat a fellow inmate to death after complaining about his poor hygiene and TV being too loud at night faces life behind bars having been convicted today of murder.

Stefan Adi was struck as many as 30 times to his head, face and neck in what was described as "unrestrained violence" meted out by Sasan Rabat while both were being held at HMP Maidstone in December 2021.

The 24-year-old's injuries included one to the jugular vein, another which tore open his windpipe, multiple skull fractures and bleeding to his brain.

They were so severe that he would have been "rapidly incapacitated" and could not have survived even with immediate medical intervention, jurors were told.

His lifeless body was discovered in Rabat's cell, wrapped in a blanket and hidden behind a locker and table.

The scene was described as one of "damage and disarray", with blood smeared on the floor, a chair broken in two and the ceramic toilet cistern lid shattered into pieces.

In contrast, Rabat was described by the prison guards that made the grim discovery as being "totally calm with no flicker of emotion".

Although the convict later accepted inflicting Adi's fatal wounds, he denied murder on the grounds of diminished responsibility.

Three psychiatrists gave evidence at his two-week trial at Maidstone Crown Court, which concluded with the unanimous guilty verdict to the charge of murder from the jury of seven women and five men.

Although Rabat will now be jailed for life, the sentencing hearing was adjourned for up-to-date reports which will enable the minimum term he will have to serve to be decided.

The court heard the two men had occupied adjacent single-bed cells at the County Road jail, which specialises in housing foreign nationals, including those in the UK unlawfully or having arrived by "irregular" means.

Adi, a convicted thief, had arrived on Thanet wing at the category C prison about three months earlier, whereas his killer, who was serving a 15-month sentence for burglary, had only been there for a week.

However, despite that short period of time, Rabat had become "increasingly antagonistic" towards his fellow inmate in the hours leading up to his death, said prosecutor John Price KC.

In a verbal confrontation witnessed by another prisoner, Rabat was said to have shouted at Adi 'You f***ing stinky b*****d. I cannot sleep because of you. Your TV is so loud'.

He also complained, as had other inmates, about his personal hygiene and insulted him by saying he "stunk of s***".

The court heard Adi's beaten body was found by prison guard Darren Cheeseman shortly before lock-up on the afternoon of December 9 after Rabat had informed him he had cut himself with a razor.

As well as having a small cut in the crease of his index finger on his left hand, his back was spattered in blood.

Once back at Rabat's cell, however, and having looked over the two pieces of furniture blocking a rear wall, the truth became clear.

The officer recognised Adi, who was just 5ft 4in and about 7st, from his joggers and Nike trainers that were sticking out from underneath the blanket.

Mr Cheeseman told the jury that on entering the cell, Rabat sat on the end of the bed and his demeanour did not change.

During cross-examination by defence counsel Jonathan Lennon KC, the prison officer agreed that it was his impression that Adi "rarely interacted" with other prisoners and that despite being "next door neighbours", the two men were not friends.

The court was told there was no CCTV in the cells or on the landings.

Two weeks before the murder, Rabat had been scheduled to have a mental health assessment.

However, the appointment did not go ahead as he had been placed in segregation after being found wandering in the "wrong part" of the prison.

Adi, who was described as "a complete loner", was declared dead at the scene by paramedics.

A post-mortem examination carried out three days later at Medway Maritime Hospital mortuary revealed the cause of death to be blunt force trauma to the head and neck.

Following his arrest, Rabat declined to answer questions when interviewed by police but gave a prepared statement in which he claimed to have acted in self-defence after Adi had threatened to kill him while wielding a razor blade.

The jury heard that no razor or blade was ever found however and Rabat's defence subsequently changed to one of diminished responsibility.

But Mr Price said it was the prosecution case that Rabat was guilty of murder, "the most serious type of homicide", he added.

It was explained by Judge Philip Statman at the start of the trial that it was for the defendant and his legal team to prove diminished responsibility.

To do so, it had to be established that it was "more likely than not" that he was suffering from an abnormality of mental functioning, that it arose from a recognised medical condition, that it impaired his ability to understand the nature of his conduct, to form rational judgement, or to exercise self-control, and that it caused or was a significant contributory factor to causing the killing of the victim.

Rabat, who was transferred from prison to high security Broadmoor in January last year, did not give evidence.

Throughout much of the trial, he sat in the dock with his head bowed and flanked by four psychiatric nurses.

Having left Iran in 2015, he arrived in the UK unlawfully on a date unknown but first came to the authorities’ attention in March 2017, whereupon he was held in a detention centre before being moved to hostel accommodation.

Records show that in the years since he has spoken to several medical experts about Kurdish persecution, witnessing his uncle's execution, suffering from flashbacks and hearing noises in his head.

He was diagnosed with post traumatic stress disorder and depression in December 2019, and in July the following year described feeling "unsafe and very anxious" when living with others.

The court was told Rabat was first convicted in September 2020 of criminal damage, and then jailed the following year in respect of two burglaries committed when he twice gained access to restricted areas at the Port of Southampton and tried to board a cruise ship.

Two months before killing Adi, he had been served with a deportation order. He became an inmate at Maidstone Prison on November 6 and moved onto Thanet wing on December 2.

Giving evidence for the defence at trial, psychiatrist Dr Vivek Bisht told the jury that Rabat appeared to have developed a paranoid psychotic illness, most likely schizophrenia, and which was likely to have been undiagnosed at the time of killing Adi.

A date for the sentencing hearing was not fixed in court but is expected to take place in about two months' time.

Remanding Rabat back into the custody of Broadmoor, Judge Statman told him: "You will be back before the court for sentence as soon as the reports that I have asked for can be prepared."

Due to the nature of the case, he also excused the jurors from further service for seven years.

The judge also commended the police officers involved in the investigation, and praised Adi's family for "honouring" their relative by attending the trial.

Of the prison officers who tended to the victim after his body was discovered, Judge Statman said he wanted them to know that they had done "everything in their power to try to save him".

Following the conclusion of the case, Detective Inspector Ross Gurden described the “brutality and violence” used in this attack as “almost indescribable”.

“Rabat beat his victim with such ferocity that he would have stood no chance of surviving,” he said.

“Rabat has not shown a glimmer of remorse for his horrific actions and our thoughts remain with Mr Adi’s family as they continue to come to terms with their loss.”