He had previously pleaded guilty on Monday, 12 April to two counts of causing grievous bodily harm, four counts of sexual assault, one count of assault by penetration, and one count of common assault.
Detective Sergeant Sarah Barrett, who led the investigation, said: “These attacks were random, and completely unprovoked. The actions of this teenager left not only his victims, but the wider community, scared and concerned for their daughters.
At 8.50am on 4 November 2020, police were called to reports of an injured girl on Moffat Road in Croydon. The 15-year-old girl had been approached by a stranger and stabbed in the leg; she was taken to hospital for treatment and later discharged.
Two days later, at 8.23am on 6 November 2020, police were called to St Paul’s Road in Croydon to reports of an injured girl. Officers and the London Ambulance Service attended. Another 15-year-old girl had been approached by a stranger and stabbed in the arm. She was treated at the scene before being taken to hospital and discharged.
Officers from the South Area Command Unit launched an investigation. The offences were linked to four other incidents from November 2019 to October 2020 where teenage girls were approached as they were walking to school and sexually assaulted or assaulted.
The boy was arrested at his residential address in Thornton Heath in the early hours of 8 November 2020.
+ Hard calls save lives. Are you close to someone on the fringes of knife crime? Do the right thing, please give information 100% anonymously through the independent charity Crimestoppers. It can feel like a hard call, but it could save the life of someone you love.