Gerald Corrigan crossbow murder: Police hold road checks
Detectives investigating the murder of Gerald Corrigan, who was shot with a crossbow outside his home, have quizzed 25 people in road checks nearby.
The retired lecturer, 74, died three weeks after being shot as he fixed a satellite dish at his Anglesey home.
People passing his home were quizzed by officers overnight.
Det Chief Insp Brian Kearney, of North Wales Police, said Mr Corrigan "died a cruel and slow death after struggling for survival for three weeks".
Drivers, cyclists and pedestrians travelling along South Stack Road, near Holyhead, were stopped between 22:00 and 04:00 BST.
An underwater search team has also carried out a search near the scene.
Mr Kearney said he believed "the answer to this crime lies with one or two key members of the public who know or have suspicions regarding the identity of the person or people involved".
He said: "We are seeking to establish any information relating to the victim, vehicles or people seen in the area at the relevant time, that might explain how Gerald came to sustain the injuries which then led to his death.
"This bank holiday weekend he should have been with his family and friends enjoying his retirement."
Mr Corrigan's family have said they could not think of anyone who would have wanted to kill him.
He worked as a lecturer in photography and video in Lancashire before retiring to Anglesey more than 20 years ago.