Knowing what resources are available and when to use them can facilitate the conduct of a criminal investigation. Existing technology allows regular exchange of information between police departments and government agencies. Agencies that may have information to make available to police departments include the following: (1) local--banks, credit unions, schools, health departments, medical examiners, personnel departments, fire departments, emergency medical services, city clerks, town halls, election boards, public administrators, housing authorities, utility companies, telephone companies, and social service departments; (2) State--State police, motor vehicle departments, corrections departments, parole commissions, and State liquor authorities; and (3) Federal--U.S. Post Office, Immigration and Naturalization Service, Department of Defense, Veterans Administration, Social Security Administration, Federal Bureau of Investigation, Drug Enforcement Agency, and the Bureau of Alcohol, Tobacco, and Firearms. Some police departments have special internal units that aid their detectives in criminal investigations. These units, such as crime scene units, computer-assisted robbery system units, criminal investigation bureaus, narcotics investigators, drug law enforcement units, warrant units, fingerprint units, ballistics units, and others, may be able to provide valuable information to aid criminal investigations. Other possible resources for police departments include foreign embassies, credit report companies, and the media. 1 photograph