A public schoolboy who attacked two sleeping students and a teacher with hammers at a boarding school has been found guilty of attempted murder.

The 16-year-old was wearing just his boxer shorts and was allegedly “on a mission” to protect himself from a zombie apocalypse when he carried out the attack.

The teenager admitted assaulting the two boys and the housemaster at Blundell’s School in Tiverton, Devon, but claimed he was sleepwalking.

Exeter Crown Court heard the youth, who cannot be identified for legal reasons, had armed himself with three claw hammers and waited for the two boys to be asleep before attacking them.

The two pupils were asleep in cabin-style beds in one of the co-ed school’s boarding houses when the defendant climbed up and attacked them shortly before 1am on June 9 last year.

Housemaster Henry Roffe-Silvester, who was asleep in his own quarters, was awoken by noises coming from the boarding house and went to investigate.

When he entered the bedroom where the attack had happened, he saw a silhouetted figure standing in the room, who then turned towards him and repeatedly struck him over the head with a hammer.

Another student heard Mr Roffe-Silvester shouting and swearing as he fled the bedroom and dialled 999 – believing there was an intruder.

The two boys were discovered in their beds a few minutes later.

They had suffered skull fractures, as well as injuries to their ribs, spleen, a punctured lung and internal bleeding.

Both are living with the “long-term consequences” of the attack but have no memory of the incident.

Mr Roffe-Silvester suffered six blows to his head.

The defendant maintained he was sleepwalking at the time of the attacks – meaning he would be not guilty of attempted murder by reason of insanity.

But the jury found the defendant guilty of three counts of attempted murder after 40 hours of deliberation.

Trial judge Mrs Justice Cutts said she would adjourn sentencing for the preparation of pre-sentence reports, including a psychiatric report, and would pass sentence on October 18.

“I don’t intend to sentence today, further reports are needed,” she said.

“I would wish a psychiatric report. That needs to be a court-ordered report.

“I can say that inquiries have been made to find somebody who would be able to write a report. It has not been straightforward because of the defendant’s age.”

During the trial, James Dawes KC, prosecuting, told jurors: “The investigation has uncovered an obsession that the defendant had with one of the boys, an obsession with hammers as weapons, and an obsession with killing and killers and the killing of children.

“He had motive, that he had planned something like this, thought about it in advance, and he was awake.

“He was using his iPad right up to the moment before the attack.”

But one expert told the jury the boy would have been sleepwalking.

Dr Mark Pressman went on to describe the attack on Mr Roffe-Silvester as “a textbook example of sleepwalking violence” and said there were no features in the case inconsistent with sleepwalking.

He also told the jury that, as the evidence supported the view that the defendant was sleepwalking when he attacked Mr Roffe-Silvester, he must also have been asleep during the attacks on the two boys because there was not time to fall into a deep sleep between the incidents.

Relatives of the defendant also told the court about a history of sleepwalking in their family.

Another expert, Dr John O’Reilly, said he did not believe the boy was asleep as a sleepwalker does not initiate violence because it is triggered by noise or touch.

Giving evidence, the boy told jurors he remembered going to sleep before the attack and then seeing the dormitory covered in blood.

“I knew something really bad had gone on and everyone was looking towards me,” he said.

“I didn’t remember doing anything so the only rational thing I was thinking was that I was sleepwalking.”

He said he kept two hammers by his bed “for protection” from the “zombie apocalypse”.

The boy added: “I feel very terribly sorry for all three individuals because of what I did to them.

“I feel very sorry for everyone, the families and themselves.”

Speaking after the verdicts, Detective Inspector Dave Egan, of Devon and Cornwall Police, described the attacks as “brutal and savage”.

He said: “This was an unprovoked attack on two schoolboys as they slept in their beds. The assaults were both brutal and savage and I believe that his intent was to kill.

“Our detectives worked tirelessly to prove that the offender had indeed been fully conscious when committing this horrendous attack – which had been pre-planned.

“I want to thank the victims and their families for their continuous support throughout this trial and to the fellow pupils and paramedics who were present on the night of the attack and offered life-saving assistance to the casualties.”

The detective thanked investigation and prosecution teams in the case for their dedication in the case.

Helen Phillips, of the Crown Prosecution Service, said the boy had a “macabre interest” in violence and had searched online for serial killers, prison and murder.

“This was a terrifying attack on two defenceless boys sleeping in their beds, who are lucky to still be alive,” she said.

“The pupil’s thirst for violence then saw him turn his attention to the housemaster, who was struck by a hammer but bravely intervened and stopped him in his tracks.

“The boy, who had a macabre interest in murder, serial killers, and violence, showed no remorse and naively thought that by concocting a story about sleepwalking at the time of the attack he could evade punishment.”

In a letter to parents, Blundell’s School headmaster Bart Wielenga said he hopes the jury’s verdicts “bring a degree of closure” for those involved.

Mr Wielenga said: “I remain tremendously proud of our school community and its response to circumstances that have been profoundly shocking and entirely unprecedented.

“No school would ever wish something like this, but the conduct of pupils, staff, parents and the wider Blundell’s community throughout the past year has only been encouraging and reassuring.”

He praised the “remarkable actions” of pupils at the school, staff, emergency services and surgeons, which he said “undoubtedly saved the boys’ lives”.

He added: “We continue to be thankful for the remarkable recovery made by all the victims and those affected by the event.

“We are mindful that the psychological wounds sometimes take longer to heal than the physical ones, and we will continue to exercise vigilance and care in supporting all the staff and pupils directly or indirectly involved.”

Mrs Justice Cutts will sentence the boy, who is now 17, on October 18.