Detectives investigating an assault outside a Leeds pub have appealed to people to come forward with photos or video taken on the premises.
A 44-year-old man from the West Park area of the city remains critically ill after he was punched to the ground outside The Skyrack in Headingley.
The attack, at 2230 BST on Saturday, followed England's World Cup match.
Police want to speak to anyone who took photos or recorded video inside or outside the premises on the night.
'In the background'
Det Supt Paul Taylor, of West Yorkshire Police's homicide and major inquiry team, said: "Given this was England's first match of the tournament and people were out to enjoy themselves with friends, lots of them will have been taking photos on their mobile phones.
"It is quite likely the person responsible for this attack or others who were with him were in and around the pub in the time leading up to the incident.
"It's possible they will have been filmed or photographed in the background of other people's photos."
Detectives are still appealing for witnesses to the incident to come forward. The inquiry team can be contacted at Weetwood police station.