CCTV images released today show the moment before an innocent teenager is murdered, because his killers mistakenly thought he was a member of a rival gang.
Kwame Ofosu-Asare wasn't.
But he was stabbed to death on a housing estate in Brixton.
Today his killers were jailed for life.
Some of you may be upset by some of the images in this report by Piers Hopkirk.
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Dozens of women gathered on Westminster Bridge to form a human chain in a show of solidarity with the victims of Wednesday's terror attack.
In a wide-ranging Peston on Sunday interview, he said Parliament security needs reviewing and the PM's counter-terror strategy is flawed.
The terror attack carried out by Khalid Masood at Westminster that left four people dead lasted less than two minutes say police.