USE OF COMPUTER-BASED MODUS OPERANDI DATA SYSTEMS (MODS)

• NCJ Number: 79
• Author(s): A ZAVALA; T H MULLEN
• Date Published: 1970
• Length: 90 pages
• Grant Number(s): 43A (41857); C42573
• Sponsoring Agency: US Dept of Justice
• Corporate Author: Cornell Aeronautical Laboratory
• Sale Source: National Institute of Justice/
• Language: English
• Country: United States of America

Annotation

A STUDY EVALUATED THE EFFECTIVENESS OF MODUS OPERANDI (MO) AS AN IDENTIFICATION TOOL.

Abstract

THE OBJECTIVES OF THIS EVALUATION WERE TO DETERMINE - 1) WHETHER ANY INDIVIDUALS USED THE SAME OR SIMILAR MO FOR SEVERAL CRIMES OF THE SAME CRIME TYPE; 2) WHETHER ONE PERSON'S MO IS DISTINGUISHABLE FROM SOMEONE ELSE'S IN THE SAME CRIME TYPE, AND (3) WHETHER THE MO FOR ONE CRIME CATEGORY IS DISTINGUISHABLE FROM THE MO OF ANOTHER CRIME CATEGORY. THE APPROACH USED WAS TO CONDUCT A SURVEY OF SYSTEMS AND DATA OF POLICE DEPARTMENTS HAVING COMPUTERIZED MO SYSTEMS, AND TO QUANTITATIVELY EXAMINE MO DATA FROM SOME OF THESE DEPARTMENTS. THE RESULTS OF THE WORK PROVIDED POSITIVE ANSWERS TO THE THREE ITEMS ABOVE. ANALYSES REVEALED THAT THE FREQUENCY WITH WHICH A PARTICULAR INDIVIDUAL USES THE SAME OR SIMILAR MO FOR SEVERAL CRIMES OF THE SAME TYPE CAN BE AS LOW AS TWO OR AS HIGH AS 44. THE ANALYSES REVEALED THAT THE MO'S OF SOME PERSONS ARE SUFFICIENTLY UNIQUE THAT SUCCESSFUL IDENTIFICATION, I.E., LEADING TO APPREHENSIONS RESULTED FROM SEARCHES OF FILES AS SMALL AS 150 CRIME CASES AND AS LARGE AS 13,000. MOREOVER, THE ANALYSES REVEALED THAT THE MO OF ONE CRIME TYPE IS USUALLY UNIQUE COMPARED TO THE MO'S OF OTHER CRIME TYPES. THIS FINDING RESULTED FROM AN ANALYSIS OF OVER 15,000 RECORDS FROM THREE SEPARATE POLICE DEPARTMENTS, SHOWING CLEARLY THAT THE NUMBER, FREQUENCY, AND COMBINATION OF MO TRADEMARKS VARY BY CRIME TYPE. IT WAS ALSO FOUND THAT IN SOME INSTANCES THE MO CAN BE SIMILAR ACROSS CRIME TYPES. THE MO SYSTEMS SURVEYED WERE FOUND TO BE COMBINATION SYSTEMS, USUALLY INCLUDING PERSONAL APPEARANCE AS WELL. IT WAS CONCLUDED THAT ESSENTIAL TO THE SUCCESSFUL USE OF MO DATA IS A COMPUTER-BASED SYSTEM PREFERABLY INCLUDING REMOTE ON-LINE TERMINALS AND RAPID DOCUMENT RETRIEVAL. IT WAS ALSO CONCLUDED THAT SEX CRIMES AND ROBBERY WOULD BE THE MOST REASONABLE CANDIDATES OF CRIME TYPES WITH WHICH TO INITIATE AN MO SYSTEM. DESIGN CONSIDERATIONS WERE DISCUSSED INCLUDING THE FEASIBILITY OF A STATE-WIDE SYSTEM, SUPPORT BY MANAGEMENT, SUPERVISORY AND USER PERSONNEL, ADEQUATE STAFF, SPACE, AND TRAINING, AND THE NEED FOR EFFECTIVENESS MEASURES. (AUTHOR ABSTRACT)