Policemen regularly sit by with crimes unfolding - a method now adopted worldwide (6,6)

I believe the answer is:

metric system

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'a method now adopted worldwide' is the definition.
I can't judge whether this defines the answer.

'policemen regularly sit by with crimes unfolding' is the wordplay.
'policemen' becomes 'met' (Metropolitan Police).
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'with' is a charade indicator (letters next to each other).
'unfolding' is an anagram indicator (untangle or unfold the original letter order).
'sit'+'by'='sitby'
The alternating letters of 'sitby' are 'sty'.
'sty' after 'crimes' is 'crimessty'.
'crimessty' anagrammed gives 'ricsystem'.
'met'+'ricsystem'='METRIC SYSTEM'

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