Material found in the bedroom of Kyle Davies contained a chilling insight into his potential plans to commit a mass shooting.
On June 18 last year, an officer from Homeland Security at Newark Airport in New York intercepted a package destined for the family home of Kyle Davies in Gloucester.
It was examined and found to contain a viable Glock 17 handgun and five rounds of expanding bullets.
Officers from the South West Regional Organised Crime Unit were alerted and arranged for a dummy package to be delivered by an undercover officer at 2.30pm on June 20.
They had no idea of the reasons behind Davies ordering the weapon until he was arrested nine hours later, when firearms officers brought him out of the property.
Davies was using software to delete his browsing history each time his laptop was closed but crucially he was using the device at the time of the arrest – meaning it contained data from that day.
This showed he had been researching Glock 17 handguns and how to clean them, the Columbine massacre, UK firearms officers and their weapons in the hours before his arrest.
A USB stick contained more than 1,000 pages of documents relating to massacres, including how-to guides on locations to choose, where to shoot people and how to make explosives.
On his bedside table was a handwritten list entitled “Gotterdammerung”, which means “twilight of the gods”, listing various equipment required for a mass shooting.
The list included a budget of £10,400 that had been transferred to his bank account ahead of him starting university a few months later.
A school text book found in his bedroom had handwritten notes inside, including one entitled “That Bastard Breivik” with stick men representing the 77 people murdered in Norway in 2011.
One page had “Hello Mr Policeman” scrawled on it, while another had “This one Mr Policeman” with an arrow pointing to a passage of writing about his mental state.
There was a Nazi marching song with the lyrics changed to refer to the River Severn instead of a German river.
Davies described the notes as “cringeworthy and rather embarrassing”.
“They weren’t intended to be seen by anyone. It was really just an exercise in boredom,” he told Gloucester Crown Court.
He told the jury that he had not thought about buying a firearm or ammunition until he began researching school shootings as they were “unusual and different”.
The teenager said his lists were to put himself “into the mindset” of mass murderers such as Eric Harris and Dylan Klebold, who committed the Columbine High School shooting.
“Dylan Klebold is the one most closely associated with me,” he told the jury.
When asked why he had drawn 77 stick people to represent those killed by Anders Breivik, he replied: “It is difficult to visualise 77 people as a unit.
“Seventy-seven people on your own is quite a lot.”
He told the court that the bomb listed on his “Phase One” note would not have detonated, before explaining the type of detonator that would be required to make it do so.