A man has pleaded guilty to the murder of a grandmother who was bludgeoned to death six years ago.
Valerie Graves, 55, was killed in a burglary-gone-wrong at a property in Smugglers Lane, Bosham, West Sussex, on 30 December 2013.
At Lewes Crown Court, 27-year-old Cristian Sabou, of Dej, Romania, admitted murder and was jailed for life with a minimum of 23 years.
Ms Graves had been house-sitting for friends when she was killed.
Prosecutor Philip Bennetts QC told the court that Sabou had entered the house as a would-be burglar, expecting it to be empty having been told a safe contained a large amount of cash and ingots.
Sabou had done jobs for the homeowners in the previous couple of months, Mr Bennetts told the court.
When he entered the home Sabou found Ms Graves, and attacked her.
He struck her with a hammer, causing horrific injuries to her head as she tried to defend herself, Mr Bennetts said.
"The level of force used was extreme. Not dissimilar from the forces experienced during road traffic collisions."
Sentencing Sabou, Judge Christine Laing QC said: "Rather than simply running away in the hope you could not be identified by a woman waking from sleep you conducted this horrific attack on Ms Graves.
"It was your dishonesty and greed that took you to the house. It was your cowardice and lack of morality that caused you to kill Valerie Graves."
She told him he would serve a minimum term of 23 years and 272 days.
Ms Graves was a mother of two who had lived in the Scottish Borders before moving to West Sussex to be nearer to family.
In a statement, her family said: "We have had to endure six years of waiting, not knowing if anyone would ever be brought to justice for this cowardly act.
"Val, our mum, was very much loved by our family and is sorely missed by all of us. She was a kind and caring person who had little conflict in her life. Her murder was incomprehensible to us all.
"Sadly, Val's mother passed away never knowing that justice has been served."
Ms Graves was last seen alive at about 22:00 on 29 December and was found in the ground-floor bedroom of the £1.6 million property.
A post-mortem examination found she had sustained severe head injuries after being hit with a claw hammer, probably around midnight.
Officers found the weapon 600 metres from the house in Hoe Lane.
Forensic analysis of DNA from the scene established the suspect was male but no match was found.
In 2015 Sussex Police launched its biggest voluntary mass DNA screening in the force's history, asking all men aged over 17 who live, work or visit Bosham to provide a DNA sample to eliminate them from the inquiry.
The screening eliminated more the 3,000 men from the investigation in which more than 9,500 people had been interviewed by police.