Explanation owed

Not many murders can have taken place in broad daylight in front of dozens of witnesses and with the culprit trapped by police inside a building and yet no one be brought to book for the crime. Yet this is what has happened with the killing of WPC Yvonne Fletcher, gunned down outside the Libyan embassy while on duty 33 years ago.

Some 18 months ago it seemed that a modicum of justice might be possible when Saleh Ibrahim Mabrouk, a former education minister under Colonel Muammar Gaddafi, was arrested in connection with the shooting. Mr Mabrouk had been among the protesters outside, rather than inside the embassy, and was later deported, only to be allowed back into the country as relations with Libya thawed. Although it was never alleged that he had pulled the trigger, there were hopes that a charge of conspiracy could be brought.

But this week, the Metropolitan Police said the investigation had been shelved because the Home Office had blocked the use of key evidence on national security grounds. There may be good reasons why this prosecution could not proceed, though it is now understood that Mr Mabrouk may have received a letter promising immunity from prosecution.

By coincidence, an appeal was launched yesterday to establish a memorial for fallen police officers at the National Memorial Arboretum in Staffordshire. Lord Stevens, the former Met commissioner, said WPC Fletcher’s family and colleagues were owed a fuller answer than they have been given so far. He is right. We are entitled to a better explanation as to why this crime has gone unpunished for so long – and why justice will now probably never be done.