Detectives hunting the killer of journalist Lyra McKee have released footage of the shooting as they appeal for help from the local community.
The 29-year-old was struck by a bullet as she was observing rioting in Londonderry on Thursday night.
Police have blamed dissident republicans for the murder and believe more than one person was involved.
CCTV captures Ms McKee’s final moments in the crowd and mobile phone footage shows the suspected gunman.
In the video, the masked attacker leans from behind cover and appears to fire shots towards police and onlookers.
Det Supt Jason Murphy, who is leading the investigation, described Ms McKee’s death as “senseless and appalling beyond belief”.
Urging anyone with information to come forward, he said: “People saw the gunman and people saw those who goaded young people out onto the streets, people know who they are.
“The answers to what happened… lie within the community.”
He said police had already received “a large number of calls and information”.
At a vigil in Derry on Friday, Ms McKee’s partner, Sara Canning, described her as a “tireless advocate and activist” for the LGBT community.
Ms Canning said her partner’s dreams had been “snuffed out by a single barbaric act” and she had been left without “the woman I was planning to grow old with”.
“The senseless murder of Lyra McKee has left a family without a beloved daughter, a sister, an aunt and a great-aunt; so many friends without their confidante,” added Ms Canning.
“We are all poorer for the loss of Lyra.”
Figures from across the political divide, including Sinn Féin leader Mary Lou McDonald and DUP leader Arlene Foster, were among the hundreds of people to attend the vigil.
One of Ms McKee’s close friends, Kathleen Bradley, told the BBC: “Lyra was a voice – she wasn’t afraid to stand up and hold her view.
“Lyra managed to get Mary Lou McDonald and Arlene Foster into Creggan [for the vigil] without any high security or barricades.
“Those politicians stood amongst us today and that really is the power of Lyra.”
Other leading figures from the worlds of politics, journalism, activism and beyond have also united to condemn Ms McKee’s murder.
Former US President Bill Clinton said he was “heartbroken by the murder”.
Irish President Michael D Higgins signed a condolence book at Belfast City Hall and spoke of the “outrage” in Ireland at the murder.
“The loss of a journalist at any time in any part of the world is an attack on truth itself,” he said.
“The circumstances in which it happened – the firing on a police force that are seeking to defend the peace process – cannot be condoned by anybody.”
The rioting that led to Ms McKee’s killing began in Derry’s Creggan area after police carried out searches for weapons and ammunition.
A gunman fired shots at police officers and the journalist, who was standing near a police 4×4 vehicle, was wounded.
She died in hospital after being taken from the scene by a police Land Rover.