A randomized experimental design involving 140 subjects was used to compare two crime reporting modes (telephonic and computer interactive). The study hypothesized that reporting mode would produce differential effects in citizen reporting of criminal behavior. The experimental condition consisted of a user-friendly, computer-activated reporting system installed and operated on personal computers. Subjects assigned to the control condition reported crime using touchtone telephones. Criminal events viewed and reacted to by subjects were reconstructed under controlled laboratory conditions. Findings revealed significant increases in reporting rates for subjects assigned to the computer reporting condition relative to the telephone reporting condition. This relationship persisted for reporting behavior at both low and moderate levels of crime seriousness. Implications of the findings for predicting future changes in the incidence and distribution of reported criminal behavior are discussed. 36 references, 2 tables, and 1 figure