Though it's a little scummy in my opinion, there's nothing illegal about the way they are monitoring for seat belt violations. You might seek a second opinion from an attorney that is more familiar with Salina City Ordinances.
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Yes, they can do that. An officer has the same right to stand on a corner that anyone else has. If he sees a violation of the law he can tell other police about it. It is not entrapment because the officer did nothing to convince the drivers to commit a crime.
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