The son from a world renown London family-run bagel firm has been arrested over the double murders of his mother and sister at their £1.5m home.
Joshua Cohen, 27, was found in a north London park after officers launched a manhunt following the discovery of the bodies of his mother, named locally as Leah, 66, and sister Hannah, 33, at the family's home in Golders Green.
The pair had been stabbed to death in what police have described as "a devastating attack".
Detectives were called at 8.50pm on Friday night to reports two women had been seriously injured and pronounced them dead at the scene.
The family run the world renown Beigel Bake in Brick Lane, London, which was set up by Mr Cohen's late father Asher with his brother and another partner in 1974 and was first Britain's first bagel bakery.
Mr Cohen had worked in the family business, which is now predominantly run by his brothers.
A family friend told the Telegraph: "I find it it quite shocking what's happened. Josh used to come and go but it was mostly his brothers Nathan and Daniel who worked there."
On his Facebook page Mr Cohen lists his last employment had been at a Costa Coffee store.
Detectives said Mr Cohen has mental health issues and suffers from paranoid schizophrenia.
His sister Hannah, who had studied psychology at City University London, was a former pupil at the prestigious Carmel College, Wallingford.
Her former schoolfriend told the Telegraph it was a "tragedy".
A neighbour said it was "sickening".
"It's absolutely sickening, the police presence afterwards was crazy so I knew something really serious had happened,"
Following a police appear, a member of the public reported seeing Mr Cohen in Golders Hill Park, north west London, yesterday afternoon.
Detectives arrested him shortly afterwards and he is presently at a north London police station undergoing questioning.
Detective Inspector Ian Lott from the Homicide and Major Crime Command said: "Following a recent media appeal a discerning member of the public alerted police to a real time sighting and officers moved quickly to detain and arrest the man wanted for questioning shortly before 2pm.
"This was a devastating attack on two women in their homes. Our investigation is ongoing."
A 44-year-old neighbour added: "I'm really shocked and upset by what has happened. I know Josh from being about. Sometimes we'd be outside and smoke a cigarette together.
"I know of his mum and sister, the family were very private.
"I knew them to say hello to but not well.
"His mum was disabled, mentally and psychically and she had a lot of help at the house.
"I've spoken to Josh and sat on the wall and had a cigarette with him - it was that type of relationship.
"I last saw Josh on Friday night when I was coming back from Sainsbury's. He crossing the road.
"He was wearing a big red hooded fleece with a logo on it and grey tracksuit bottoms and was heading towards the tube station."
Formal identification and post mortem examinations have yet to take place but police are confident they know the identify of the victims.
Their next-of-kin have been informed.
Staff at Beigel Bake were too upset to talk last night.
Mr Cohen senior, who died in December aged 81, arrived in the UK from Israel in the 1960s and worked at his brother's bakery next door initially before branching out and opening his bagel business.
Beigel Bake, famed for its salted beef bagel, started out as a wholesale business and almost everything was made by hand in traditional Jewish style.
It remains a 24 hour bakery and produces 7,000 bagels everyday.