The United States Postal Inspection Service (or USPIS) is the law enforcement arm of the United States Postal Service. Its jurisdiction is defined as "crimes that may adversely affect or fraudulently use the U.S. Mail, the postal system or postal employees." An agency with 4,000 employees, 2,000 criminal investigators, an armed uniformed division, forensic laboratories and a robust communications system, the USPIS is a major federal law enforcement agency that leads and assists in numerous joint federal and state investigations.