Detectives trying to reconstruct the last moments of a gunman who killed a police officer have issued an appeal for information.
Pc Dibell, 41, was shot dead near his home in Clacton, Essex, last week. His suspected killer, Peter Reeve, 64, was found dead the following day.
Today, Essex Police said people who were in the Chelmsford area on the evening of July 9 and the morning of July 10 may hold the key to piecing together Reeve's movements.
Officers now believe Reeve was in Chelmsford at 9pm on July 9 - just five hours after a major manhunt was launched to find him.
Detective Chief Inspector Simon Parkes said: "We know Peter Reeve got a train from Colchester to Chelmsford at approximately 7.30pm on Monday, July 9, and tried to visit friends and family in the Melbourne area a couple of hours later.
We then have no further sightings until we found his body in the grounds of All Saints Church in Writtle at 8.30am the following morning. This was after a gunshot was heard.
"We need to find out how Peter Reeve got to Colchester and how he came to be in Writtle on Tuesday morning.
Anyone with information is asked to contact Colchester's major investigation team on 101 or email firstname.lastname@example.org