The most common and most likely answer to this crossword clue is the 9 letter word ARRESTING
I've seen this crossword clue in The Guardian
A
R
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More clues leading to the result ARRESTING
- Striking? Police officers are doing it regularly
- Impressive undertaking for Bobby?
- Strikingly attractive actor must be gutted not working
- Impressive responsibility of the police
- Remarkable policeman’s activity?
- Stopping for breather in a boxing arena
- A queen not currently acting as striking
- Copper’s work, remarkable
- Lovely job of a police officer
- Dramatic artist rolling over and not getting up?
Buddy explains!

The straight part
We know that "Impressive/responsibility of the police" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case impressive/responsibility of the police = arresting.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ARRESTING mean?
ARRESTING verb- To stop the motion of (a person or animal).
- To stay, remain.
- To stop or slow (a process, course etc.).
- To seize (someone) with the authority of the law; to take into legal custody.
- To catch the attention of.
- To undergo cardiac arrest.
- Striking, gripping