Newspaper writing is not always formal and styles vary from paper to paper, depending on the target audience. Using a word like “collared” is not uncommon – newspaper style is not exactly the same as any other style of written English. From Wikipedia:
Note that this article appeared in a “tabloid” newspaper. Tabloid writing can be quite informal, and it is often over-dramatic. I suspect in this case, the journalist used the word because it is police jargon. He also used the slang term, "busted" and refers to the police as "cops". I would be somewhat surprised to see that language used in this sense in a non-tabloid paper - The New York Times, for example.Terms and structure
Journalistic prose is explicit and precise, and tries not to rely on jargon. As a rule, journalists will not use a long word when a short one will do. They use subject-verb-object construction and vivid, active prose (see Grammar). They offer anecdotes, examples and metaphors, and they rarely depend on colorless generalizations or abstract ideas. News writers try to avoid using the same word more than once in a paragraph (sometimes called an "echo" or "word mirror").
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