Home Secretary Theresa May joined police officers of all ranks as they paid tribute to a colleague shot dead as he went to the aid of a member of the public.
Hundreds of people packed St James Church in Clacton-on-Sea to remember Pc Ian Dibell, 41, who was killed near his home.
The memorial service was attended by Pc Dibell's family, chief constables from neighbouring police forces, rank and file officers, and members of the public.
Officers from Essex Police held a guard of honour at the entrance to the church.
Pc Dibell's girlfriend, police community support officer Louise Lilley, his sister-in-law Nicole Dibell, and Essex chief constable Jim Barker-McCardle were delivering tributes during the service.
A message of condolence from the Prince of Wales was read to the congregation.
More top news
Heavy showers will affect many places this morning but it will brighten up this afternoon. Feeling cooler than the last few days.
Following the hottest day of the year so far, it will be a muggy night. Showers will develop this evening and will continue tomorrow.
The Duke and Duchess of Cambridge have been in Luton today, to continue to raise awareness on mental health.