Recordings are a good idea and usually end up exonerating the officer in question. So much so that if he did any research on it, the results would shake CR out of his frenzy. But no, in a country as large and diverse as the U.S., recording isn't mandatory everywhere.

Banquo, please don't base your perceptions of U.S. law enforcement on law enforcement dramas. As a former instructor of mine says: "Don't waste your time with novels."