One of Britain’s most prolific sex offenders, a serving London police officer has admitted to committing 24 counts of rape over the course of an almost two-decade campaign of abuse against women.

David Carrick, 48, was accused by the Metropolitan Police and the country’s prosecution service of using his position of authority to frighten and manipulate his victims by telling them that no one would believe their story against that of a serving officer.

The Met police, already grappling with a collapse of confidence among the public after a string of scandals, apologized 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.

“This is an appalling case and the prime minister’s thoughts are with all of his victims,” Sunak’s spokesman said. “Police forces must root out these officers to restore the public’s trust, which has been shattered by high profile events such as this.”

Met Assistant Commissioner Barbara Gray said the pattern of abusive behavior should have been spotted earlier.

“Because we didn’t, we missed opportunities to remove him from the organization,” she said. “We are truly sorry that Carrick was able to continue to use his role as a police officer to prolong the suffering of his victims.”

Carrick, who joined the Met in 2001, isolated women socially and financially, and often held them against their will, controlling what they wore and when they slept.