Detectives investigating a stabbing in Whitehawk on Friday are urgently trying to find William Miller.
Anyone who sees him is being asked not to approach him but to call 999 immediately.
Emergency services were called to Whitehawk Close on Friday at around 12.25pm and found a man with significant injuries believed to have been caused by a bladed weapon.
He was taken to hospital by the ambulance service for treatment.
Police are now urgently trying to locate William Miller, 42, of Whitehawk Close, in connection with the incident.
Detective Inspector Ian Lucas said: “This was a violent assault in the middle of the day, that left the victim with multiple, significant injuries.
“A fast-moving investigation was launched immediately. If you see William Miller or know of his whereabouts, do not approach him but call 999 quoting Op Elson.
“Anyone who witnessed anything suspicious around the time of the incident is also asked to contact police online or via 101.”
I thought Neanderthals had died out
Hand yourself in William.