The chief of London’s Metropolitan Police has said “everyone in policing” feels “betrayed”, after a serving police officer pleaded guilty on Friday to the murder of Sarah Everard in March.

Wayne Couzens’ admission, at a hearing at the Old Bailey in London, followed his previous guilty pleas entered in June to the kidnap and rape of Everard, 33, who disappeared on the evening of March 3 as she walked home from Clapham Common to Brixton.

Dame Cressida Dick, the Met’s chief, said in a statement that the force was “sickened, angered and devastated” by Couzens’ “truly dreadful crimes”. “Everyone in policing feels betrayed,” she added.

Dick apologised to the Everard family, saying the thoughts and prayers of the Met were with them. “I was able to speak to [the family] earlier today and said how very sorry I am for their loss and their pain and their suffering.”

Following Couzens’ plea, the Independent Office for Police Conduct announced it had served 12 misconduct or gross misconduct notices on police officers over various aspects of the case.

Everard’s disappearance stirred up a national debate about the safety of women and girls in the UK, including the very low rates of conviction for sexual violence offences.

The IOPC’s inquiry looked at alleged failures by the Met to properly explore two allegations of indecent exposure against Couzens in London in February 2021, for which two officers are being investigated for possible misconduct, and another alleged incident in Kent in 2015, the IOPC said.

Kent Police’s assistant chief constable, Tom Richards, said his force had contacted the IOPC over the alleged incident in Dover in June 2015. The allegation involves a complaint by a man that another man was driving naked from the waist down, he said.

Couzens, who is from Deal in Kent, had been a Metropolitan Police officer since transferring to the force from the Civil Nuclear Constabulary in September 2018. He had been working since February 2020 in the parliamentary and diplomatic protection command, mainly protecting embassies.

The Met on Friday confirmed Couzens had passed the necessary vetting processes when joining the force.

“The checks confirmed there was no information available to the MPS at the time that would have changed the vetting decision,” the force said.

Sal Naseem, the IOPC’s regional director for London, said his office shared the horror that many people were feeling knowing that Everard’s killer was a police officer who had taken an oath to uphold the law and protect life and property.

“The offences Wayne Couzens has admitted add up to the worst betrayal of the public’s trust,” Naseem said.

The Met said it had stopped paying Couzens after his previous guilty pleas, the earliest point at which it was able to do so.

Couzens was remanded in custody and will be sentenced on September 29. He also faces a police disciplinary hearing.