Plans by two teenagers to carry out a shooting attack on a school amounted to "real-life intent" rather than "childish fantasy", a court has been told.
The 15-year-old boys are on trial at Leeds Crown Court accused of plotting to murder pupils and teachers in Northallerton, North Yorkshire.
Prosecutor Paul Greaney QC claimed the elder boy had been inspired by the Columbine school massacre.
The pair deny conspiracy to murder.
They also deny alternative charges of intentionally encouraging or assisting an offence and encouraging or assisting an offence believing it would be committed.
Summing up, Mr Greaney told the jury that the older defendant had "revelled" in the 1999 US school shooting in Colorado, which saw 12 students and a teacher killed.
Mr Greaney claimed that the teenagers who were responsible for that attack, Eric Harris and Dylan Klebold, had left clues as to what was to come, such as internet searches for weaponry and, on Harris's part, a journal "espousing a far right-wing ideology".
'Case to answer'
The prosecutor drew parallels with evidence that was found in relation to the two friends accused of the Northallerton plot, including a diary written by the older of the pair which reflected a "homicidal state of mind".
Questioning why the boys had not given evidence, Mr Greaney told jurors: "It is obvious that the prosecution case against each of the defendants is sufficiently strong to call for an answer from them, and there is no sensible reason for them not to give evidence other than that they cannot answer the prosecution's case."
Discussing what he would have asked the older of the two boys, he said: "Why did you write in your diary that you wanted to carry out a school shooting if that's not what you intended?
"Why, we would have asked, did you tell the police that you were disgusted by the Columbine massacre when actually you revelled in it?"
The trial continues.