A Welsh teenager has been found guilty of plotting a terror attack on the day of a Justin Bieber concert in Cardiff at Principality Stadium.

The17-year-old boy who cannot be named due to his age was arrested on June 30th, hours before the concert began. According to The Guardian, the boy had researched the level of security that would surround a Bieber concert and wrote a “martyrdom letter” which read “I am a soldier of the Islamic State. I have attacked Cardiff today because your government keeps on bombing targets in Syria and Iraq. There will be more attacks in the future.”

Police raided the boys South Wales home and found a claw hammer and a gutting knife in his school rucksack.

Birmingham Crown Court jurors were also told that the boy had written a note that had points such as “run down the non-believers with a car” and “strike the infidels who oppose Allah in the neck”, However, the defendant claimed that he was only interested in gore, and did not intend on carrying out the terrorist attack. He insisted that it was sheer curiosity, stating “I wanted to see how easy it was for people who had an interest in terrorism to go online and get information because the police and the government are trying to crack down on terrorism and radicalisation. I wanted to see if it was possible, not for me but from someone else’s point of view.”

However, investigations into the boys’ internet history painted a different light, with the police finding that the defendants interest in ISIS began a year before in June 2016, where it was found he was searching for details about ISIS fighter names JIhadi John, alongside looking up the attacks that took place in London, France, and Germany. By June of this year, the boy was posting images encouraging a terrorist attack in Cardiff, via Instagram.

Although the boy pleads innocence and says his actions were down to curiosity, Sue Hemming, from the Crown Prosecution Service says “this teenager’s behavior over many months leaves no doubt that he intended to kill and maim as many people as possible in an attack reminiscent of the incident on Westminster Bridge. The CPS presented overwhelming evidence that he was prepared to die for an extremist worldview and he will now rightly face the prospect of a substantial prison sentence.”

The boy will remain in custody until a hearing on January 18th, 2018.