Police: Criminal Investigations

Along with physical evidence, witnesses, and suspects, there are a number of other sources that can provide useful information in a criminal investigation. These include psychological profiling, crime analysis, and the general public.

In the last two decades, psychological profiling has received much media attention. It is often portrayed as a complicated yet foolproof method of crime solving. In reality, psychological profiling is not all that mysterious. Psychological profiling is a technique for identifying the major personality, behavioral, and background characteristics of an individual based upon an analysis of the crime(s) he or she has committed. The basic theory behind psychological profiling is that the crime reflects the personality and characteristics of the offender much like how clothes, home decorations, and the car you drive reflects, to some degree, your personality. And these preferences do not change, or do not change very much over time.

In constructing a psychological profile, the characteristics of the offender are inferred from the nature of the crime and the behaviors displayed. The elements of a psychological profile are essentially statements of probability as determined from previous crimes and crime patterns (Holmes). Profiles are best suited and most easily constructed in cases where the perpetrator shows indications of psychopathology such as lust and mutilation murder, sadistic rape, and motiveless fire setting.

The value of a psychological profile is that it can help focus an investigation or reduce the number of suspects being considered. In this respect, a psychological profile is much like most physical evidence; a psychological profile cannot identify a suspect when one is not already known. There has been very little systematic research that has documented the actual impact of psychological profiles on criminal investigations. In an internal examination by the F.B.I. (as reported in Pinizzotto, 1984), analysts examined 192 cases where profiling was conducted. Of these, 88 were solved. Of these 88 solved cases, in only 17 percent did a profile offer significant help. Given the limitations of psychological profiles, it is clear that they are not as useful as media depictions might suggest.

Crime analysis is another potentially powerful source of information in a criminal investigation. Simply defined, crime analysis is the process of identifying patterns or trends in criminal incidents. Various means can be used to reach such ends, from computer mapping technology to computer data banks. The Violent Criminal Apprehension Program (VI-CAP) of the Federal Bureau of Investigation is an example of an elaborate and sophisticated crime analysis system. When police departments are confronted with unsolved homicides, missing persons, or unidentified dead bodies, personnel in the department may complete a VI-CAP questionnaire, which asks for detailed information regarding the nature of the incident. These data are then sent to the F.B.I. and entered into the VI-CAP computer system, which is able to collate the data and possibly link crimes that occurred in different jurisdictions based on similarities in the crimes. This system, and similar intrastate systems, are designed to facilitate communication and sharing of information across agencies.

Finally, the general public is a potentially useful source of information in criminal investigations. As defined here, the public consists of people who have information relating to a particular crime or criminal but often cannot be identified through traditional methods (like a neighborhood canvass). Crime Solvers (or Crime Stoppers) tip lines and television shows such as America's Most Wanted provide a method of disseminating information and encouraging individuals to come forward with information relating to particular crimes. Although once again, little systematic research has examined the actual effects of such strategies, information that has come from the general public through these sources has led to the solving of many crimes across the county (Rosenbaum; Nelson).