A manhunt is under way after a mother and daughter were found stabbed to death in their home.
The women, aged 66 and 33, were pronounced dead at a property in Golders Green, north London, on Friday night.
The Met said officers were looking for Joshua Cohen, 27. He was known to the victims.
Mr Cohen has mental health issues including paranoid schizophrenia. The Met said he should not be approached.
He is described as white, 5ft 9in tall, with cropped hair and stubble. He was last seen wearing a red Nike sweatshirt with a white logo on it.
He was also wearing white trainers and dark grey trousers or tracksuit bottoms.
Detectives added that he had recently shaved off his hair and eyebrows.
No arrests have been made.
Next-of-kin have been informed and post-mortem examinations will be carried out soon.
Det Insp Ian Lott said: “This was a devastating attack on two women in their home.
“The individual we are seeking was known to them and from all the information we have, acted alone. I would urge anyone who saw anything in the local area at the time of the attack to get in touch with investigators immediately. Likewise, if you spot Joshua Cohen please call police on 999.”
Det Ch Supt Simon Rose from Barnet added that he wanted to reassure residents that officers were doing everything they could to find him.
“High-visibility foot patrols have been stepped up in the area and police will be on hand to listen and respond to community concerns,” he added.