Floundering badly, Theresa is tested by the police (12)

I believe the answer is:

breathalysed

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'tested by the police' is the definition.
I can't tell whether this definition defines the answer.

'floundering badly theresa' is the wordplay.
'floundering' indicates anagramming the letters (letters flounder or move around).
'badly'+'theresa'='badlytheresa'
'badlytheresa' with letters rearranged gives 'BREATHALYSED'.

'is' acts as a link.

Can you help me to learn more?

(Another definition for breathalysed that I've seen is " Tested for drink-driving".)

I've seen this clue in The Telegraph.

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