A MASS DNA screening programme by detectives hunting the killer of a North Yorkshire man has begun today.

Officers probing the murder of 58-year-old bachelor David Williamson, from Sutton-on-the-Forest, delayed starting to ask for samples from about 80 villagers in Sutton-on-the-Forest and nearby Huby from yesterday to today after a request from the Home Office Forensic Science Service, based at Wetherby.

The service needed extra time to put systems in place to ensure DNA samples from this inquiry could not be mixed up with thousands of other samples being tested at the labs.

Samples taken from villagers are only to be tested against the DNA profile isolated from evidence discovered at the roadside path where Mr Williamson was found unconscious and dying from a fractured skull on March 26. They are then to be destroyed at the end of the inquiry.

Acting Detective Inspector Kevin Ross said: "This was a very minor delay. We and the Forensic Science Service just want to be absolutely sure that everything is in place to make certain the integrity of these tests cannot be faulted."

Taking a sample is a quick and painless process which involves a plastic swab being placed inside a person's mouth.

DI Ross added: "We are hoping people will see we are doing this to catch David Williamson's killer and that we need their help to do that."

Updated: 11:34 Tuesday, August 07, 2001