Murdered officer left without protection

1.25pm Two armed officers patrol New Palace Yard square.

1.29-1.42 Armed officers last seen at Carriage Gates 60 minutes before attack.

1.44 Changeover for one of the armed officers on duty. Pc Ashby and Pc Sanders patrol together.

1.54 Both officers out of view of CCTV cameras. They remain off camera for 46 minutes until they hear the sound of Masood’s car crashing into the railings.

2.40 Both armed officers seen walking towards the scene.

2.41 Masood enters the grounds of Parliament and kills Pc Palmer.

2.42 Masood is shot by a plain-clothes police officer.

2.42 One hour after armed officers last at Carriage Gates, Pc Ashby and Pc Sanders walk towards where Pc Palmer has been fatally wounded.