A 27-year-old man has been arrested after a mother and her daughter were stabbed to death at their home in Golders Green.
Police were called to a house in Golders Green Crescent on Friday night and found two women, aged 33 and 66, who appeared to have been stabbed to death.
A spokesperson for the Metropolitan Police said: “Both women were pronounced dead at the scene.”
“While we await formal identification, officers are confident that they know the identity of the victims and that they are mother and daughter.”
Joshua Cohen was arrested in Golders Hill Park on Saturday afternoon when a member of the public alerted police following a media appeal.
Mr Cohen is believed to be the son of the founder of Beigel Bake in Brick Lane, east London.
His mother and sister are being named locally as Leah and Hannah.
His sister Hannah is understood to have studied psychology at City University London and was a former pupil of Carmel College, Wallingford.
Detective Inspector Ian Lott said: “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 14:00hrs.
"This was a devastating attack on two women in their homes. Our investigation is ongoing."
Mr Cohen, who detectives said has mental health issues and suffers from paranoid schizophrenia, lost his father in December.
The dad died aged 81, having arrived in the UK from Israel in the 1960s.
He founded his bagel business which is a popular and well known destination for partygoers in east London, due to it being open 24 hours a day.
A 44-year-old neighbour told the Telegraph he was "shocked and upset by what has happened.
"I know Josh from being about. Sometimes we'd be outside and smoke a cigarette together."
The neighbour said the family was very private.
"I knew them to say hello to but not well.
"His mum was disabled, mentally and physically 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."
The Met said it would not confirm the identities of the victims until formal identification and post mortem examinations had been carried out.
But police are confident they know the identify of the victims.
Detective Chief Superintendent Simon Rose described the incident as "horrific" and assured the local community that police were increasing security in the area.
He said: "High visibility foot patrols have been stepped up in the area and police will be on hand to listen and respond to community concerns. We will continue to work with the CST and keep them fully updated with significant developments. "