A schoolboy plotted to carry out a Columbine-style massacre on the 15th anniversary of the atrocity, the Old Bailey was told today.
The 17-year-old, accused of planning to launch a terror attack on his old school in Loughborough, Leicestershire, also downloaded and kept a photograph of the pair who murdered 12 students and one teacher at Columbine High School in Colorado, United States in 1999.
The teenager, who was diagnosed with Asperger syndrome after his arrest, had considered killing himself, and other people, as he felt angry and depressed earlier this year, the court heard.
But he denied wanting to copy the Columbine killers during his cross-examination.
Prosecutor Max Hill QC told the court the teenager intended to carry out his attack, which he referred to himself as "the operation", on April 20, 2014.
Asked if that was correct, the defendant, wearing a black T-shirt and jeans as he sat in the dock, replied: "Quite possibly, yes."
He denied April 20 was a significant date for him as it was the day of the Columbine killings and the day Hitler was born.
Mr Hill asked if by next April the defendant intended to have a gun licence. He replied: "Possibly, yes" and also told the court he wanted a licence and wanted to buy firearms.
Asked why he had the picture of Klebold and Harris, he said: "Because it was to do with Columbine and part of history."
The teenager was found to have petrol bombs, air rifles, pistols and armour at his home which he planned to use against staff and pupils at the school in Loughborough, it is alleged.
He also named his college, a local mosque, a cinema, Loughborough University and the town's council offices as potential targets, it is claimed, and is alleged to have written a "hit list" of people he intended to target.
Photographs of the teenager making a military-style salute outside a mosque in Loughborough and outside a leisure centre, on which he had spraypainted the words "No more mosques", were shown to the jury.
In the leisure centre picture, he is also holding a machete.
He told the court he had been making the salute, with an arm raised up in the air, after seeing Norweigan mass killer Anders Breivik making a similar gesture. Newspaper cuttings of reports about the murderer's trial were found in the teenager's bedroom after his arrest.
Mr Hill asked the youth why had wanted to copy Breivik, to which he replied: "I thought it was a cool salute."
He also said he posed with a machete because he "thought it would be cool", the court heard.
The teenager admitted today to having shown a pistol to a group of strangers on a boat.
He said the incident happened at some point in early 2012 but he was not sure when.
The court heard he sent a text message to a friend reading: "So, pulled a pistol on people before."
In a message sent to a friend on Facebook about the event, he also wrote: "Looked scared. They were on a boat. LOL."
The defendant, who cannot be named for legal reasons, denies a charge of possessing items for the purpose, preparation and instigation of an act of terrorism.
They include nine partially assembled petrol bombs, a quantity of commercial firework powder, a quantity of part-assembled pipe bombs, partially constructed improvised explosive devices (IEDs), quantities of commercial pyrotechnic fuse cords, a stab-proof vest, a gas mask, three 0.22 air rifles, one Olympic 0.22 blank-firing pistol and a quantity of ammunition, one 0.22 air pistol, three BB guns, a black military belt containing air gun pellets and a silver cartridge, and one notebook containing information about the planning and construction of explosive devices, it is alleged.
The teenager also denies one count of possessing a document or record containing information likely to be useful for a person committing or preparing an act of terrorism, and a further count of possessing explosives in the form of component parts of IEDs.
He and two other 17-year-old boys have already pleaded guilty to two charges of possessing petrol bombs and component parts of pipe bombs for the use of explosive devices.
The jury heard that last December the defendant wrote a Facebook message to a friend in which he referred to "getting his own back".
It read: "I always think to myself 'Why bother living anyway?'
"I think 'Spend your life getting stuff together then, one day, you get your own back. It will be worth the wait'."
He ended the message with a smiley face emoticon, the court was told.
That month he also sent a message about the Columbine killers, writing: "Still got their message across by killing 13 people and it's one of the most famous massacres ever."
The youth had a book called Spree Killers and had written a note which he inserted inside it, reading: "This is my favourite book and some of the people in this book have inspired me to be who and what I am."
He had added: "If anyone is in a bad situation in life, then read this book and some or all of the people in this book will inspire you to take necessary action."
Asked what he meant by "necessary action", the teenager, who was accompanied in the dock by two court intermediaries while being cross-examined, said he was "not entirely sure".
He also told the court the book had taught him about bullying. The jury has previously heard that the teenager had suffered from bullying at several schools.
In text messages to his friend last November, the defendant spoke about the Virginia Tech massacre in 2007, saying: "Feel sorry for the guy who done it. His confession video is sad."
Asked why he felt sorry for him, he replied "because they were bullied".
The teenager made notes in his 2012 diary about killings around the world, the court was told.
As well as newspaper reports on Breivik, cuttings about other murderers, including Cumbria killer Derek Bird, were also found in his bedroom. On his wall was a picture of John Lennon's killer Mark Chapman, the court heard.
The youth cited Catcher In The Rye as one of his favourite books, with the prosecutor noting that Chapman claimed to have been inspired by the novel.
The trial was adjourned until Monday morning.