SARAH YOUNG A serving London police officer has admitted carrying out 24 counts of rape in a nearly two-decade-long campaign of abuse against women, making him one of Britain's most prolific sex offenders. The Met police, already grappling with a collapse of confidence among the public after a string of scandals, apologised for failing to spot the pattern of abuse earlier. A spokesman for British Prime Minister Rishi Sunak called the case "appalling" and London Mayor Sadiq Khan said serious questions needed to be answered after Carrick pleaded guilty to 49 charges relating to 12 victims between 2003 and 2020.…