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.
More top news
Police want to find four boys seen on CCTV around the time of the attack.
Georgina Ferguson was on a carriage behind the one that was bombed. This is her very personal story of 7/7.
David Cameron unexpectedly appeared during a cookery segment.