A sixth teenager has been charged with the murder of 16-year-old Shakilus Townsend who was stabbed to death in south London last week, police said on late on Saturday.
Detectives said the 17-year-old teenager is due to appear before Sutton Magistrates Court on Monday.
Townsend was found with a stab wound in the entrance to a block of flats in Thornton Heath last Thursday. He died in hospital the same night.
Last week five teenagers, including one girl, appeared in court charged with his murder. Tyrell Ellis, 18, two other youths aged 16 and 17, and a 15-year-old girl were remanded in custody.
A 22-year-old man has been released on police bail until a date in August pending further investigations.
Townsend is one of 20 teenagers to die violently in the capital this year.
The Metropolitan Police have said knife crime is now the force's top issue, but have denied London was in the grips of a stabbing "epidemic", feared by politicians and the news media.
On Thursday there were four fatal stabbings in a single day in London, bringing the total killed with knives in the capital this year above 50.
Officers say they have searched 27,000 people, arrested more than 1,200 and seized 500 knives in London during a six-week crackdown. A 75-strong team has also been set up to target those carrying weapons.
