Former Metropolitan Police officer Wayne Couzens has pleaded guilty to the kidnap and rape of Sarah Everard.
The Old Bailey was told the ex-parliamentary and diplomatic protection officer also accepted responsibility for the killing of 33-year-old Ms Everard.
However, he was not asked to enter a plea to a charge of murder when he appeared in court on Tuesday.
Marketing executive Ms Everard went missing as she walked home from a friend’s house in Clapham, south London, on 3 March this year.
She was reported missing by her boyfriend on 4 March and her body was found in a large builder’s bag hidden in an area of woodland in Ashford, Kent, a week later.
A post-mortem examination earlier this month revealed Ms Everard died from compression of the neck.
The Metropolitan Police officer, 48, was wearing khaki trousers and a grey sweatshirt as he appeared by video link from Belmarsh jail.
He pleaded guilty to kidnapping Ms Everard “unlawfully and by force or fraud” on 3 March.
He also pleaded guilty to a second charge of rape between 2 and 10 March.
Couzens was not asked to enter a plea to her murder between the same dates.
The defendant replied “Guilty, sir” when asked for his plea to the first two charges.
The court heard that responsibility for the killing was admitted but medical reports were awaited.
Members of Ms Everard's family sat in court to witness the defendant enter his pleas.
A further hearing before Lord Justice Fulford is due to take place on 9 July.
Ms Everard’s death sparked a national debate about female safety and hundreds gathered for a vigil in her memory at Clapham Common.
Additional reporting by PA
