Police have recovered a weapon from the scene in Edmonton but would not confirm reports that the knife was a machete.
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Prince Harry has paid tribute to the Prince of Wales for the care he showed to him and the Duke of Cambridge after Diana's death.
Rain in the north tonight. Mostly dry, mild and humid elsewhere.
Wayne Lotter was co-founder and president of the PAMS Foundation, which was credited with helping to arrest thousands of poachers.