THE NCIC IS THE MOST COMPLETE AND BEST UTILIZED NATIONAL COMPUTER SYSTEM AND WAS ESTABLISHED AS A SERVICE TO ALL LAW ENFORCEMENT AGENCIES AT THE LOCAL, STATE, AND FEDERAL LEVELS. THE SYSTEM OPERATES BY MEANS OF COMPUTERS, DATA TRANSMISSION OVER COMMUNICATION LINES, AND TERMINAL DEVICES. ITS OBJECTIVE IS TO IMPROVE THE EFFECTIVENESS OF LAW ENFORCEMENT THROUGH EFFICIENT HANDLING AND EXCHANGE OF DOCUMENTED POLICE INFORMATION. THE NCIC IS TO SERVE AS AN INDEX FOR THE EVENTUAL DEVELOPMENT OF COMPUTERIZED LAW ENFORCEMENT INFORMATION SYSTEMS IN ALL STATES. DATA STORED IN THE NCIC COMPUTER BANK MUST MEET CERTAIN CRITERIA THAT CONCERN VEHICLES, WEAPONS, PROPERTY, AND WANTED PERSONS. THE LETS IS A COMMUNICATION SYSTEM CONNECTING THE MARYLAND INTERAGENCY LAW ENFORCEMENT SYSTEM (MILES) WITH THE LETS HEADQUARTERS AND MESSAGE SWITCHING CENTER IN PHOENIX, ARIZ. THIS CONNECTION ENABLES MILES USERS TO REQUEST DRIVER'S LICENSE INFORMATION FROM OTHER STATES, THE DISTRICT OF COLUMBIA, AND CANADA. MILES USERS ARE ALSO ABLE TO USE THE LETS TO SEND ADMINISTRATIVE MESSAGES TO ANY OTHER LAW ENFORCEMENT OR CRIMINAL JUSTICE AGENCY IN THE COUNTRY. MILES CONTAINS RAPID STORAGE UNITS FOR WANTED AND MISSING PERSONS AND STOLEN PROPERTY. IT HAS OVER 70 TERMINALS IN ITS NETWORK THROUGHOUT THE STATE OF MARYLAND. AN ADDITIONAL COMPUTER HOOKUP LINKS MILES AND THE WASHINGTON AREA LAW ENFORCEMENT SYSTEM (WALES). MILES PROVIDES MESSAGE SWITCHING CAPABILITIES THAT ENABLE EACH COMMUNICATION TERMINAL OF THE NETWORK TO COMMUNICATE WITH ANY OTHER COMMUNICATION TERMINAL. PRINTOUTS SHOWING BOTH INJURIES AND ANSWERS FROM THE COMPUTER ARE NECESSARY IN ESTABLISHING PROBABLE CAUSE FOR THE ARREST OF AN INDIVIDUAL. THE MILES-WALES INTERFACE CONSISTS OF A BISYNCHRONOUS COMMUNICATION LINE. COMBINED COMPUTER TELECOMMUNICATIONS OF NCIC, MILES, WALES, AND LETS HAVE MESHED THEIR NETWORKS TO AID ALL LAW ENFORCEMENT AGENCIES IN THE DETECTION OF CRIME AND CRIMINALS. AN ILLUSTRATION OF MILES AND A SAMPLE PRINTOUT FROM THE SYSTEM, ALONG WITH A BIBLIOGRAPHY, ARE INCLUDED. (DEP)