A man has admitted plotting to steal a quad bike before the death of PC Andrew Harper.
The Thames Valley Police officer was killed on August 15th near the village of Sulhamstead in Berkshire. He'd been responding to reports of a burglary.
The twenty eight year old had been dragged under a van and died from multiple injuries.
He'd been married just four weeks before.
Henry Long, who's 18 and from Mortimer in Reading and two 17-year-old boys - who cannot be identified - are charged with his murder, an alternative of manslaughter and conspiracy to steal a quad bike.
A fourth defendant, Thomas King, who's 21 and from Basingstoke, is accused of conspiracy to steal a quad bike.
Three of the defendants appeared at the Old Bailey by video link from custody while King was in the dock before Mr Justice Edis.
During the hearing, King pleaded guilty to conspiracy to steal on or before August 15th.
He was granted bail until his sentencing at the conclusion of the trial of the other defendants.
One of the 17-year-olds, wearing a grey tracksuit and large crucifix, entered not guilty pleas to manslaughter and conspiracy to steal.
He was not asked to enter pleas to the further charge of murder.
A further plea hearing for Henry Long and the other 17-year-old will take place in the new year.
A six-week trial has been scheduled to start at the Old Bailey in March.