The person who shot a 74-year-old man with a crossbow, causing him to suffer "horrendous injuries", has been urged to come forward.
Gerald Corrigan was struck outside his home in a remote area near South Stack Road in Holyhead, Anglesey, at about 00:30 BST on Friday.
He is critically ill at Royal Stoke University Hospital after the bolt went through his upper body and right arm.
North Wales Police said the person should "do the decent thing".
Det Ch Insp Brian Kearney, said: "I am appealing to the person who discharged this weapon to come forward."
He added: "This is an impartial search for the truth and I have no doubt that any person who discharged such a weapon accidentally at a human being would be significantly traumatised.
"You will be treated professionally by myself and my team of officers."
A major incident team with more than 30 staff is dealing with the incident.
Det Ch Insp Kearney also appealed to the public to inform the force of anyone they know who owns a crossbow and was on the island on 18 and 19 April, including visitors.
"We are asking our retail community if they sell crossbows, bolts or accessories in north west Wales, namely Anglesey or north Gwynedd, to also come forward so that we can conduct enquiries in that regard," he said.
"I have lived in Anglesey for 22 years. It is a safe area. I have never come across anything like this."
On Saturday, the family of Mr Corrigan, a former photography and video lecturer who has lived on Anglesey for more than 20 years, made an appeal.
They said: "We cannot think of anybody who may have wanted to hurt our father and dear partner. We are trying to come to terms with this shocking incident."