A 46-year-old man was arrested on the afternoon of Saturday, 1 July on suspicion of murder and attempted murder. He remains in custody at a north London police station.
Police were called at 11.33pm on Thursday, 29 June to Elthorne Road, N19 to reports of a stabbing.
Officers responded with paramedics from the London Ambulance Service.
A 15-year-old boy was found with stab wounds. Despite the efforts of medical staff he was sadly pronounced dead at the scene, just after midnight.
He has been named as Leonardo Reid from Islington.
It was established that another victim, a 23-year-old man, had also suffered stab injuries. He had been taken to a west London hospital, where he too was pronounced dead.
Officers have informed the next of kin of both victims. They are being supported by specially trained officers.
Post-mortem examinations will be conducted in due course.
A third victim, believed aged 28, was also located at an address in N19. He had suffered a stab wound. He was taken to a north London hospital where he remains. His condition is not thought to be life threatening.
Detectives from the Specialist Crime Command are leading the investigation, supported by colleagues from the Central North Command Unit.
Anyone who has information that could help police should call 101 or tweet @MetCC quoting reference CAD 9383/29Jun.
To remain 100% anonymous please call the independent charity Crimestoppers on 0800 555 111.
