Two 15-year-old boys who plotted to murder pupils at their school in a re-enactment of the 1999 Columbine massacre have been given custodial sentences after a judge told them they had  “intended to cause terror on the scale of a school shooting in America”.

The teenagers, who can now be named as Thomas Wyllie and Alex Bolland, were said to have been influenced by the “poisonous effect of the internet” when they developed a hero-worship towards Eric Harris and Dylan Klebold.

The boys were said to have been so obsessed by the murderers, who took arms and killed 13 people at the Columbine High School in Colorado, that they devised a similar plan at their school in Northallerton, North Yorkshire.

A page from a diary kept by the older boy
A page from a diary kept by the older boy (North East CTU/PA)

They were said to have developed their plan so extensively that they had a “hit list” of targets who had either bullied or wronged them, with prosecutors claiming that they had downloaded bomb-making manuals, researched weapons online and warned friends about what was to come.

Addressing Wyllie, who was said to have been the ring-leader of the pair, the judge told him: “You saw yourself as someone outside the system, someone special.”

Making comparisons between the defendants and their idols, she said: “Those two saw themselves as anti-heroes, with the power to choose who lives and who died.”

The jury heard how Wyllie discussed his motivations for the plan in a diary which espoused what jurors were told was his “twisted ideology”.

A screengrab of chat between the two boys
A screengrab of chat between the two boys (North East CTU)

The inside cover of the book, which was recovered from the teenager’s home in October 2017, apologises for either committing “one of the worst atrocities in British history” or killing himself.

Mrs Justice Cheema-Grubb said that the journal’s entries were “desperately sad words for a 14-year-old boy with a family”.

In a secret hideout in Catterick Garrison, he had kept a rucksack filled with screws, boards and flammable liquid, which prosecutors suggested were instruments for making an explosive device which was to be part of the killing.

According to Paul Greaney QC, prosecuting, the bullying that Bolland suffered from was a motivation for the attack, saying: “In other words, they were driven by a desire for revenge.”

School attack court case
The contents of a rucksack that was found by officers searching the secret hideout (North East CTU/PA)

After a Snapchat conversation discussing details of the plot came to light in September 2017, he made “clear and unvarnished confessions” to a teacher and police, claiming that his targets were “infecting the gene pool” and that they were doing a “service to society”.

However, the pair were not arrested until October 2017, after Wyllie’s secret hideout was found by officers.

Following a trial at Leeds Crown Court, they were both convicted of conspiracy to murder by the jury, with Wyllie additionally being convicted of the unlawful wounding of a teenage girl.

On Friday, he was given a 12-year custodial sentence, with an additional licence period of five years, while his co-defendant Bolland was handed a ten-year custodial sentence.

Richard Pratt QC, defending Wyllie, claimed that the teenager did not agree with the jury’s verdict, but added: “He has recognised that which he did, even on his own account, caused a great deal of terror to a number of people, a great deal of hurt and a great deal of harm.”

In defence of Bolland, Tom Price QC told the court that he was “a follower rather than a leader”, claiming that the teenager would not have become involved in the plot had he not met his co-defendant.

The judge expressed her concerns that the teenagers had been so heavily influenced by viewing extensive internet material on the Columbine killers.

She said: “It is self evident that the unchecked consumption of such material on the internet is capable of poisoning young minds to such an extent that two disaffected murderers, who killed themselves after ending the lives of innocent people, can become the focus of adulation and imitation.

“Children, particularly otherwise alienated children, need to be taught better than they must exercise self-control in surfing the internet, for their own safety and mental health.”

She said: “The conspiracy to murder, of which you have been convicted, was not wishful thinking or a fantasy. It was a real plot.”

The judge told the boys: “Both of you inhabited narrow lives in which you saw yourselves as victims and it is clear that, rather than be positive influences on each other, you entered into a noxious relationship which pulled each other down further into a selfish obsession with punishing others for the wrongs you felt had been perpetrated against you.”