A second person has been arrested on suspicion of murder following the stabbing of a 17-year-old girl in an east London park.
Jodie Chesney was attacked while playing music with friends in Harold Hill, Romford, on 1 March.
On Thursday, hundreds of people marched through the town centre to protest against her killing.
A 20-year-old man arrested in Leicester on 5 March on suspicion of murder also remains in custody.
Jodie was with five other teenagers near a children’s playground in Harold Hill at about 21:00 GMT when they became aware of two males who they did not speak to.
The pair then left, but about 30 minutes later they returned and walked straight towards the group where one of them stabbed the victim in the back.
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A post-mortem examination gave the cause of the Scout’s death as trauma and haemorrhage.
The 17-year-old’s father said she lost “so much blood” in the “ferocious attack” and that clearly “someone meant to murder her”.
Describing his daughter as a “proud geek” and a “great girl”, Peter Chesney called on anyone who knew the killer to “just dob them in, grass them up.” For more information visit Leedsteleghraph.