Police Commissioner Bernard Hogan-Howe will visit a school in Edmonton today that was blighted by knife crime.
Negus McClean was stabbed to death by a gang a year ago, following a fight over a BlackBerry mobile phone.
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"Three were standing together almost shoulder-to-shoulder in like a little wolf pack and they're staring at me...", said PC Wayne Marques.
Her nails had curled around three times before embedding in her pads.
The death toll from the Grenfell Tower fire is currently believed to be around 80 people, the vast majority of whom were from just 23 flats.