"London's murder rate has overtaken New York City's for the first time ever as the twelfth person has been killed in just 19 days. February marked the first month in history books that London had more murders than the American city with a total of 15 homicides...Mayor of London Sadiq Khan requested an urgent meeting with the Prime Minister and Commissioner of the Metropolitan Police Service to discuss what can be done 'to tackle the evil of knife attacks on Britain's streets'."You can notice the emphasis. It's not the actual criminal that needs to be addressed. It's the weapon.
Good luck with that. Edged weapons have been around, to coin a phrase, since the Stone Age.