A second person has been arrested on suspicion of murdering teenager Jodie Chesney, who was stabbed in the back as she socialised with friends in a park.
Scotland Yard said a 17-year-old male is in custody after being arrested in London on Friday morning.
Jodie, 17, was in the park in Harold Hill, east London, when she was approached by two males and knifed from behind in a seemingly motiveless attack on March 1.
She was pronounced dead just over an hour after officers were called to what police described as a "savage, evil attack" at about 9.25pm.
A 20-year-old man arrested in Leicester on Tuesday evening remains in custody on suspicion of murder in London, police said.
Jodie was playing music with five other teenagers in the park when they became aware of two males who left at around 9pm without interacting with them, the Metropolitan Police said.
About 30 minutes later, the pair returned and one stabbed Jodie in the back without saying a word, officers added.