A man stabbed his ex-partner's mother to death then left a chilling message in blood before leaping from the top floor of a city centre car park, a police source said.
His victim was named locally as Carol Berry, 66, who was knifed at her semi-detached bungalow in the Bradley area of Huddersfield, West Yorkshire, at about 6.40pm on Friday.
He also stabbed her 36-year-old son, named by locals as Andrew Field, who remained in hospital with non-life threatening injuries.
The 40-year-old attacker, yet to be formally identified by police, then travelled 30 miles to a multi-storey car park in Hanover Street, Manchester, where he jumped to his death from the eighth floor shortly after midnight yesterday.
Written in blood on a wall was the chilling message: "F*** you Claire."
A source said the message was linked to the murder investigation, and was thought to be directed at the man's ex-partner, named locally as Claire Tootill.
It was understood the couple had split acrimoniously.
"It is not known if the woman who died was the intended victim," the source said. "But she might well have been."
Police believe no-one else was involved in what they described as a "targeted" and "domestic-related" attack.
A West Yorkshire Police spokesman said: "Detectives investigating the murder of a woman in Huddersfield have confirmed they are not seeking anyone else in connection with the inquiry after a man was found dead in Manchester.
"While a formal identification of the man is still to take place, officers believe he is a 40-year-old man whose identity is known to them."
The killer was not thought to have links to the West Yorkshire area.
Ms Berry's home was cordoned off yesterday and a police officer stood at the end of her drive.
Blood could be seen smeared on her white front door.
The property was well-shielded from view by conifers, and neighbours said the owner "kept herself to herself".
Meanwhile in Manchester, the spot from where the killer jumped was unguarded by police, and more blood could clearly be seen on railings.
The West Yorkshire Police spokesman said officers were liaising with Greater Manchester Police.
"It is believed he had fallen from the roof," the force said.
"The death is not believed to be suspicious."