An 18-year-old man has admitted to killing Thames Valley Police officer PC Andrew Harper.
Henry Long appeared at the Old Bailey via video link from Belmarsh prison where he denied murder but pleaded guilty to manslaughter and conspiracy to steal a quad bike.
When asked for his plea to a charge of manslaughter, he said: “Pardon, was that manslaughter?” before adding: “I plead guilty, guilty.”
The 28-year-old officer died from multiple injuries after being dragged under a van at around 11.30pm on August 15 last year.
He had been attending a reported burglary near the village of Sulhamstead while on duty in Berkshire.
Long, who is alleged to have driven the vehicle that killed PC Harper, appeared in court alongside a 17-year-old co-defendant.
The boy, who cannot be named because of his age, joined the hearing by video link from Wetherby young offenders institute and pleaded not guilty to manslaughter and conspiracy to steal.
Previously, another 17-year-old boy entered not guilty pleas to manslaughter and conspiracy to steal.
The three teenagers are due to face a six-week trial at the Old Bailey from March 9.
A fourth defendant, Thomas King, 21, from Basingstoke, has admitted conspiracy to steal a quad bike.
Newlywed PC Harper had been married to his wife Lissie for just four weeks when he died.
In a tribute to her husband, Mrs Harper said he was the “kindest, loveliest, most selfless person”.
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