None of the children who heard Will Cornick boast that he was going to kill Spanish teacher Ann Maguire has ever been quizzed about why they did not tell anyone.
The inquest into Mrs Maguire’s death heard how, in the classes immediately before the tragedy, Cornick told 10 other pupils what he was going to do to the teacher and also his plan to kill other members of staff.
He showed four children the 34-inch knife on that morning, told some of them of his plan a couple of days before the attack and, months before the stabbing. He exchanged Facebook messages with one of his friends expressing his loathing for the 61-year-old teacher and offering "a tenner" to kill her.
But none of these children told a member of staff about any of this before Mrs Maguire was murdered.
Since then, none have ever been asked why they did not disclose this information - including in the inquest which finished yesterday.
Det Supt Nick Wallen, who led the murder inquiry, told the inquest he was so concerned that these children may feel like they were being blamed for the tragedy that he specifically instructed his detectives not to ask them why had not immediately reported Cornick’s chilling boasts.
And the school’s headteacher, Steve Mort, told the week-long hearing that he also never asked the children the same question, adding that he was not aware of the full extent of the disclosures Cornick made to his schoolmates on April 28, 2014, until pre-inquest hearings earlier this year.
Coroner Kevin McLoughlin decided that the children should not be brought to court to be questioned because it would be too traumatic.
This decision was challenged by lawyers acting for Mrs Maguire’s husband, Don Maguire, and their four children.
The case went all the way to the Court of Appeal where judges upheld the coroner’s ruling.
The inquest jury heard lengthy extracts from the statements of the children.
One girl told police Cornick said "I don’t want to hurt her, I want to kill her."
According to another teenager, Cornick said: "He was sort of saying he looked at the human body and how to kill people because he wanted to kill them fast."
The pupil said Cornick told him this was so he could go from Mrs Maguire to other teachers - Sinead Miley, who was pregnant, and Andrew Kellett.
The boy said in his statement: "He was going to stab Miss Miley in the stomach because she was pregnant and wanted to kill the baby instead."
Another boy said he did not know why he did not immediately report that Cornick had a knife.
The boy said: "I was in shock. I did not really know what to do.
"I know I should have told someone, but in the room I was in there wasn’t any teachers supervising us."
One teacher, Emma Conway, said: "It beggars belief that they wouldn’t share that information.
The hearing heard how some children just did not believe Cornick was serious while others said he also threatened them.
An inquest was only held at all because Mr Maguire pushed, saying he wanted a public examination of the evidence.
The company director said he could not simply accept the "narrative" that Cornick’s murderous attack came "out of the blue" with nothing to forewarn anyone.
Mr Maguire told the inquest he did not want to blame anyone, but to make sure the facts had been thoroughly examined so lessons could be learned.