The son of a murdered East Finchley pensioner is calling for 'someone's head to roll' after a Crown Prosecution Service blunder in the case against the man accused of killing his father.

Retired taxi driver Leonard Harris, 79, of Aylmer Road, was attacked by Michael Weir in a burglary in May last year at the home he shared with his wife Trudie, also 79. But Weir, from Hackney, was cleared of murder on appeal when a judge ruled that a DNA sample linking Weir to a blood-stained glove was legally inadmissible.

The reason given is that the DNA sample was gathered during a separate investigation into a drugs charge from which Weir was previously acquitted.

The frustration at that verdict was compounded when the pensioners' son Frank Harris, an advertising executive, wanted to take the case to the House of Lords the last court of appeal but the CPS missed its deadline for filing the papers.

Mr Harris, who wrote a letter of complaint to the Director of Public Prosecutions, Mr Calvert-Smith, on March 2, told the Times Group: "I'm furious and want somebody's head to roll as I feel the way we have been treated is disgusting."

The letter accuses the CPS of causing Mr Harris and his family 'considerable anguish' for ruining his chance of an appeal after the papers were filed one day late.

It states: "Since the debacle concerning the Court of Appeal ruling you've caused me and my family considerable anguish, mental trauma and depression that I had hoped I had overcome following the initial jury verdict. It makes me even sicker to feel that the perpetrators in your organisation are seemingly getting away scot-free."

A CPS spokeswoman said: "We're awaiting a report from an internal investigator and will be sending Mr Harris a reply very shortly."