THE DIGITAL COMPUTER'S METHOD OF OPERATION USING A BINARY NUMERICAL SYSTEM IS EXPLAINED. ALSO DISCUSSED ARE BOOLEAN ALGEBRA, LOGIC GATES, METHODS OF INPUT, PROGRAMMING, THE CENTRAL PROCESSING UNIT, STORAGE IN MEMORY UNITS, THE OUTPUT STAGE, THE COMMUNICATION PROCESS, AND HEURISTIC PROGRAMS. THE COMMON TYPES OF COMPUTER CRIMES ARE DELINEATED, INCLUDING THOSE INVOLVING PHYSICAL ATTACKS ON COMPUTERS; THE USE OF THE COMPUTER TO INTIMIDATE OR DEFRAUD; ITS USE TO STEAL MONEY, BONDS, NEGOTIABLE INSTRUMENTS, OR PROPERTY; THEFTS OF COMPUTER DATA; AND ILLEGAL USE OF COMPUTER TIME BY EMPLOYEES. A COMPOSITE PROFILE OF A COMPUTER ABUSER AND THE MOTIVATIONS BEHIND THE CRIME ARE EXPLORED. PROBLEMS APPARENT IN THE PROSECUTION OF COMPUTER CRIMINALS ARE DISCUSSED, WITH SPECIFIC REFERENCE TO THE EASE WITH WHICH COMPUTER EVIDENCE MAY BE ERASED, THE FREQUENT LACK OF ASSISTANCE BY THE COMPANIES INVOLVED, THE LACK OF AN AUDIT TRIAL, PROBLEMS SURROUNDING THE ADMISSIBILITY OF COMPUTER EVIDENCE AND SEARCH AND SEIZURE. TRIAL PREPARATION AND TECHNIQUES ARE DESCRIBED; THE USE OF CLEAR, NONTECHNICAL LANGUAGE IS RECOMMENDED. SUGGESTIONS ARE ALSO MADE FOR COMPUTER SECURITY. INCLUDE ARE 160 FOOTNOTES, A GLOSSARY OF COMPUTER TERMS, AND BIBLIOGRAPHY WITH OTHER 30 REFERENCES. A WARRANT AND AN EVIDENCE FORM ARE APPENDED. (TAG)