The PSNI have released CCTV footage of events which led up to the moment a Northern Irish journalist was shot and killed.
Lyra McKee was killed while PSNI officers were carrying out a search operation in Derry last night.
The search was connected to disrupting dissident republicans ahead of this weekend's commemoration of the 1916 Easter Rising.
Over 50 petrol bombs were reportedly thrown at police during the night of unrest.
To help with the investigation, the PSNI released this footage, where a gunman is seen and which shows Lyra in a crowd of onlookers last night as she was reporting from the scene.
"Lyra’s death is senseless and appalling beyond belief. It represents the tragic loss of promise and the loss of potential, however it should not be the loss of hope," said Detective Superintendent Jason Murphy
"We know that the people of Creggan do not support what happened and they stand with us today in outrage and disgust at the mayhem that took place on their streets last night."
Vigils in memory of Lyra are taking place in Derry and Dublin this evening.