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.
In the United States, the FBI (Federal Bureau of Investigation) and other federal agencies such as the United States Secret Service, US Marshals, United States Park Police, United States Capitol Police, and the United States Pentagon Police are limited to the enforcement of federal laws and usually specialize in certain crimes or duties, but do enforce some state laws.