Quotation marks would only have to be used on thoughts if the<br />thoughts were someone else's. If the thoughts came from a book, computer source, or some other source, then quotation marks should be used. However, the writer of the essay does not have to quote his or her <i>own</i> thoughts.
As of 2011, there are at least 25,000 sworn (and armed) law enforcement officers working for federal agencies not traditionally associated with law enforcement, and 3,800 of them were specifically criminal investigators.
Federal law enforcement authorities have authority given to them under various parts of the United States Code (U.S.C.). Federal law enforcement officers enforce various laws, generally at only the federal level. There are exceptions, with some agencies and officials enforcing state and tribal codes. Most are limited by the U.S. Code to investigating matters that are explicitly within the power of the federal government.