A teenage burglar jailed for at least 32 years for the murder of a granddad has had his minimum term slashed by appeal judges.

Top judges said Aaron De Silva's youth at the time of the killing justified the cut - despite his long record of serious crime. Now 21, De Silva, of Warwick Road, Earls Court, was 19 when he murdered 73-year-old Joseph Griffiths in November 2012.

The much-loved father and grandfather died at his home after being dealt nearly two dozen stab wounds. Convicted of murder, De Silva was told he would serve a minimum of more than three decades behind bars before being eligible for parole. But three top judges at the Court of Appeal cut the ‘excessive’ term to 28 years on Wednesday.

“We have no doubt that a minimum term of 32 years for a young man who killed when aged 19 is a very severe sentence, and perhaps uniquely so,” said Mr Justice Blake.

The court heard Mr Griffiths was woken early at his home in Hazlebury Road by someone breaking in. He went to investigate and was attacked by De Silva, who stabbed him 22 times in a desperate bid to get away. Sentencing at the Old Bailey, Judge Timothy Pontius said he was convinced De Silva intended to kill.

At the Court of Appeal, barrister Michael Holland QC told a panel of three judges that the killer's mitigation had not been properly taken into account. He had a troubled background, including domestic violence and the imprisonment of his father. His own criminal career began at the age of 12 and progressed from damaging property to robbery and assaults, via weapons crime and burglary.

Giving judgment, Mr Justice Blake said: “This was a dreadful crime where a much-loved husband and father was brutally attacked in his own home by an offender intent on aggravated burglary.

“Nevertheless, his age at the time is a significant factor in mitigating his culpability. Young offenders are more likely to be impulsive, unthinking, and respond to situations with excessive and gratuitous force.

“Whilst his personality disorder does not diminish his culpability for his deliberate acts and use of deadly force, along with his youth it may explain his failure to have learned lessons from previous encounters with the law.”

The decision means De Silva can apply for release after serving the 28-year term.