John Monckton's murder is one of several recent killings where people have been stabbed in their own homes in affluent districts of the capital.

A Metropolitan police study, reported in the Guardian last month, found that more than 6,600 crimes in London in the year to May involved a knife, 80% of which were carried out by teenagers. Police chiefs think knives are increasingly fashionable among the young because of Scotland Yard's success in tackling gun crime and the stiffer five-year mandatory sentence for possession of firearms.