A 15-year-old boy who was jailed for shooting promising student Shereka Marsh dead has had his sentence slashed by three of the country’s top judges.

The boy, who killed the 15-year-old Urswick School pupil with a single bullet at a property in Hackney Wick in March last year, lost a Court of Appeal bid to clear his name on Thursday last week.

But his sentence was slashed and he will now probably only serve four-and-a-half years behind bars before being automatically released.

He was convicted of manslaughter and firearms crimes at the Old Bailey last September and was jailed for nine years, with a further five to serve on extended licence after release.

At the Court of Appeal last week, his barrister Timothy Raggatt QC argued that his conviction – on the basis of gross negligence – was ‘arguably unsafe’, and said the case hinged on what a 15-year-old boy could be expected to do to make sure that the gun was safe.

“What the jury didn’t get was assistance on how to deal with this case, given that they did not accept the fundamental case of murder,” he said.

But appeal judge Sir Brian Leveson, sitting with Mr Justice Cranston and Mr Justice Singh, rejected the boy’s bid to clear his name.

He did, however, say it was wrong to term the youth “dangerous” and quashed the extended licence portion of his sentence, meaning the boy can be released from prison much sooner.

The teenager had admitted he had been given the gun to keep by an older man and thought, with the magazine – the gun’s storage device – removed, it was harmless.

But there was already a bullet in the breach and, when it discharged, Shereka was shot in the neck and died.