Northumbria Police released the picture of Leighton Amies, 15, after he was convicted of killing 14-year-old Tomasz Oleszak.
Leighton Amies claimed he was attacked while walking a friend home through Whitehills Nature Park, and said he did not know he had stabbed Oleszak in the chest.
Prosecutors said his claim of being attacked was a lie and a jury at Newcastle Crown Court found him guilty of murder on Monday 17 April.
“There is a public interest in trying to deflect young people from the carrying of knives, when that happens, this kind of utterly tragic outcome can occur”, said Judge Justice Spencer.
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