The Defense Criminal Investigative Service is the criminal investigative arm of the Office of the Inspector General, U.S. Department of Defense. DCIS protects military personnel by investigating cases of fraud, bribery, and corruption; preventing the illegal transfer of sensitive defense technologies to proscribed nations and criminal elements; investigating companies that use defective, substandard, or counterfeit parts in weapons systems and equipment utilized by the military; and stopping cyber crimes and computer intrusions.