Murderer may have lain in wait for twin

A man wanted for four murders may have killed one of his victims before lying in wait for her twin sister, it emerged today.

As the nationwide hunt for suspected killer Mark Hobson entered its fifth day, it was revealed that his girlfriend Claire Sanderson had been missing from work a fortnight before her battered body was discovered in the one-bedroom flat they shared.

Concerned about her violent relationship with Hobson, her sister Diane, 27, is believed to have visited the property in Camblesforth, near Selby, North Yorkshire, where she was strangled to death and found alongside her twin on Sunday-morning. Within hours of the discovery the bodies of housebound pensioners James, 80, and Joan Britton, 82, were found stabbed to death 25 miles away at their detached home in Strensall, near York.

"The pathologist thinks it's possible Claire was killed some time before Diane," said a police source. "The theory is that the killer may have either lured her to the flat or lain in wait for her."

Hobson, a divorced father-of-three who drank heavily, has not been seen since the bodies of the Sanderson sisters were found although he is thought to be hungry, penniless and without a passport or transport.

Police said they had seized CCTV tapes from petrol stations, town centres and other locations in a bid to catch Hobson. Yesterday, two women were arrested in Selby following reported sightings of the 34-year-old former binman.

Police said that Hobson - who has a two-inch scar over his left eye - may be heading for the North Yorkshire moors where there are many isolated cottages. He had been reading a SAS survival book.

Friends say Hobson will not allow himself to be captured alive by police.