The most common and most likely answer to this crossword clue is the 9 letter word VIOLATION
I've seen this crossword clue in The Times
V
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O
L
A
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More clues leading to the result VIOLATION
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The straight part
We know that "Law infringement" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case law infringement = violation.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 VIOLATION mean?
VIOLATION noun- The act or an instance of violating or the condition of being violated.