Summary: Despite Defense Department (DOD) actions to correct inventory management weaknesses, discrepancies persist between military records and GAO's physical count of highly sensitive handheld missiles. Moreover, these weapons remain vulnerable to insider theft because DOD does not always open a representative sample of containers during maintenance checks. GAO was able to match its physical count of handheld rockets with military records, but it found oversight weaknesses with these weapons as well. For example, the Marine Corps reported that three rockets were missing from shipments returning from the Persian Gulf War. The Naval Criminal Investigative Service reached no conclusions about whether the rockets were missing, lost, or stolen, and the investigations were closed. Moreover, the armed services have different procedures and requirements for overseeing the rockets. If DOD is to effectively oversee these sensitive weapons, it needs to establish an integrated, general ledger controller system, which links DOD's accounting systems with its logistics and other key management systems. GAO did not find any evidence that terrorists or other extremists had stolen any highly sensitive handheld missiles, rockets, munitions, or explosives from military arsenals. DOD personnel, however, have stolen grenades, C-4 explosives, and TNT.