Police are hunting a man who raped a woman in her own home in the early hours of Saturday morning.
The man in his 20s managed to get into the house in Oakwood Park, Livingston, through an unlocked door.
He threatened those inside with a knife before subjecting the 39-year-old owner to a rape that lasted almost two hours, before leaving about 0700 GMT.
Inquiries show the man had tested other properties in the same street before he finally found one unlocked.
Police have urged locals to makes sure their homes are secure. They have also stepped up their presence in the area.
The man was described as being 6ft tall, with short, dark hair and "chunky" sideburns.
He was wearing a cream hoodie top with the word Crosshatch across the chest and a large pouch at the front.
He also had on a blue baseball cap and jogging bottoms.
Det Insp Alan Somerville, of Lothian and Borders Police, said: "The attack has left the victim seriously traumatised, and she is being supported by family and specially-trained officers.
"We are undertaking regular high-visibility patrols in the area where the attack took place, in order to provide reassurance to local residents.
"House-to-house inquiries over the weekend have established that the suspect had tested other properties in the street before gaining access to the victim's home through an unlocked door."