Three teenagers have been charged with the murder of Pc Andrew Harper who was killed while responding to reports of a burglary.
Henry Long, 18, and two 17-year-olds who cannot be named due to their age, were all charged with the Thames Valley Police officer's murder.
All three were also charged with conspiracy to steal a quad bike, as was 21-year-old Thomas King.
All four will appear at Reading Magistrates' Court on Thursday.
Pc Harper was killed in the line of duty on August 15 in Sulhamstead, Berkshire, just four weeks after he got married.
The 28-year-old died from multiple injuries after being dragged under a vehicle.
Another man, 20-year-old Jed Foster, has already appeared in court having been charged with murder.
He is next due to appear in custody at Reading Crown Court on November 20.