Shafiq Smith, of Brudenell Avenue, Tooting Bec, was arrested in Mitcham on October 19 and charged with murder and attempted murder.
He was also charged with threatening a person with a bladed or pointed article in a public place.
Appearing at the Old Bailey on Tuesday (January 9), the 18-year-old pleaded not guilty to all charges.
A 17-year-old boy, who remains anonymous for legal reasons, was also charged with murder and threatening a person with a blade or pointed article in a public place.
The teenager also pleaded not guilty to both counts at the Old Bailey the same day.
Both defendants will appear at the Old Bailey for trial on Monday April 16.
Oluwafemi Omotosho, of Fulham, previously pleaded guilty to possession of a blade or sharp pointed article in a public place and affray.
The 19-year-old has had his sentencing adjourned until the outcome of the trial.
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