The killer of a Lincolnshire schoolboy has failed in his High Court appeal to reduce the minimum number of years he must serve in prison.
Luke Walmsley, 14, was stabbed through the heart by fellow pupil Alan Pennell, who was also 14, at Birkbeck College in North Somercotes in November 2003.
Pennell, now 23, was detained for life for murder and ordered to serve at least 12 years in 2004.
Mrs Justice Cox said Pennell had to "continue to progress" in prison.
The court heard Pennell had "a fascination with knives" and used one of his collection of 12 blades to kill Luke Walmsley.
Pennell submitted his appeal to cut the number of years he must serve before he can be considered for parole, on the grounds of his good behaviour in prison.
His lawyers said he now had insight into his crime, had taken numerous courses - including anger management - had achieved five GCSEs and now had a documented aversion to knives.
But Mrs Justice Cox refused to accept that Pennell's conduct was so "exceptional" as to justify a cut in his 12-year-tariff.
"There is much that is most encouraging in these reports," she said. "Pennell has certainly matured... he has worked consistently and well educationally.
"However, whilst the evidence viewed as a whole demonstrates good and steady progress, there clearly remain in his case, significant issues to be addressed."
The ruling means Pennell must wait until November 2015 before he can apply for parole.