Thames Valley Police 'shocked and saddened' by officer killing
Speaking at a press conference following the death of PC Andrew Harper, Thames Valley Police Chief Constable John Campbell said it was a "terrible day" for the force.
PC Andrew Harper, who got married four weeks ago, died at about 23:30 BST on Thursday in Berkshire, when he was "dragged along by a vehicle" while attending a reported burglary.
Read more: Killed PC was 'dragged by vehicle'