A judge has ruled that a French man will not be tried for killing two British backpackers in an Australian hostel in 2016 because of mental illness.

Smail Ayad is not criminally culpable for the knife attack at Home Hill in Queensland state, Justice Jean Dalton decided in the Mental Health Court in Brisbane on Thursday.

Mia Ayliffe-Chung, 20, from Wirksworth in Derbyshire and Tom Jackson, 30, were killed.

Mr Jackson, from Congleton, Cheshire, was injured while shielding Ms Ayliffe-Chung and died seven days later in hospital.

Mia Ayliffe-chung was killed while working in Australia (Tommy Martin/PA)
Mia Ayliffe-chung was killed while working in Australia (Tommy Martin/PA)

The court decided Ayad should not face trial because he was suffering paranoid schizophrenia and thought local farmers and hostel staff were trying to kill him.

Ayad will be held in a mental health facility until he is sent to France.

The the victims were included on a US list of 78 global attacks that the White House said were “executed or inspired by” the Islamic State group and under-reported by the media.

Ms Ayliffe-Chung’s mother, Rosie Ayliffe, responded with an open letter to President Donald Trump rejecting the decision to label her daughter’s death as a terror attack.

“My daughter’s death will not be used to further this insane persecution of innocent people,” she wrote.

Police had said that Ayad shouted “Allahu akbar” — an Arabic phrase meaning “God is great” — during the attack, but that there was no indication that he had been motivated by extremism.

In August 2016, Ayad, then 29, dragged Ms Ayliffe-Chung from her hostel bed and stabbed her repeatedly in front of dozens of backpackers and then stabbed the hostel manager in the leg.

Ayad then jumped from a balcony, fracturing his spine, before stabbing a dog to death and then inflicting fatal wounds to Jackson, who was trying to shield Ms Ayliffe-Chung.

Justice Dalton said killing the dog was telling.

“This was an extraordinary action and I think, in the context of all this offending, points to how frightened he was and how ill he was,” she said.

Ayad smoked up to four marijuana cigarettes a day for years before the attack and was under the delusion that 50 local farmers and hostel staff wanted to kill him and burn his body in a pizza oven, lawyers told the court.

“He thought that a cleaner at the hostel had told him he would be killed when he went to check out and he thought the owner of the hostel was making excuses as to why he couldn’t leave,” Justice Dalton said.

“He interpreted her as telling him that he had to die,” she added.

Ayad had been charged with two counts of murder, one count of attempted murder, one count of serious animal cruelty and 12 counts of serious assault.