The jury was told both boys were lucky to survive their injuries, and prosecutors said the attacker’s intention must have been to kill.
But the court heard both victims had been permanently altered as a result of the attack and their cognitive function is no longer the same.
After attacking his two schoolmates, the defendant then struck housemaster Henry Roffe-Silvester, who tried to stop him, it is alleged.
‘Intention must have been to kill’
Opening the case, James Dawes, KC, prosecuting, told the jury: “The defendant was awake, and he decided to put into action a plan that he had been fermenting in his head for some time.”
“And that plan was to kill the two boys, and he decided to do it whilst they slept in their own beds, and he decided to do it with a hammer.
“It is not known which boy he attacked first.
“The defendant was in possession of four claw hammers - a heavy hammer with a flat striking side and two-pronged claw at the back.
“He had four of them, and he selected more than one hammer and he quietly climbed up into the top of the first cabin bed.
“The boys are asleep, and they had both had their heads on pillows, and then he smashed a hammer or hammers into their heads as they slept, multiple times.
“He also hit arms and backs. He didn’t just use the flat end of the hammer - he used the claw end as well, to strike these boys.
“These blows smashed their skulls.”
Dawes went on: “The defendant’s intention must have been to kill both boys. Astonishingly, they both survived.”
“Their survival was due to the prompt arrival of astonishingly professional paramedics and the skilful work of the doctors and surgeons to save their lives.
“The two boys were, however, very badly injured, and sadly neither will be completely the same again. Their heads are permanently damaged and their cognitive function not as it was.
“Mercifully, neither victim has any memory of these attacks because both were attacked in their sleep. They recall going to bed and then waking in hospital.”
Defendant appeared to be ‘on a mission’
Roffe-Silvester heard a noise and, when he went to investigate, was also attacked around the head with a hammer.
Dawes explained: “He was shouting at the defendant to stop. In total, there were six impacts to his head.”
“He said the defendant was expressionless - he was neutral and unsettling in his expression and appearance.
“Roffe-Silvester said he thought the defendant appeared to be ‘on a mission’, and afterwards his face and body relaxed, and he was calm and slumped on his feet, squatting against the wall.”
Another student was told to “keep an eye” on the defendant in the matron’s office, Dawes said.
“The defendant told him he was feeling quite stressed about things before the incident, with school tests, and [he] owed some money to a girl,” he said.
“The defendant told the student he had hammers and he had been watching horror movies lately, and he had them to protect himself.”
Dawes said the defendant told the student he had fallen asleep after watching a movie and then carried out the attack while he was sleeping.
The prosecutor suggested this was a lie because there was evidence the boy was using his iPad until moments before the alleged assaults.
“The student tried to calm the defendant down and asked him again what had happened, and the defendant said to the student he was watching horror movies and he had weapons to prepare for the zombie apocalypse and to protect himself,” Dawes said.
Blundell’s is a co-educational private boarding school in Tiverton, Devon that takes male and female day and boarding pupils.
The defendant, who is now 17, denies three counts of attempted murder against his two roommates and Roffe-Silvester.
His family sat in the public gallery.
The trial continues.
