Like the FBI, Investigative Psychology’s (IP) concern is in proving that personality characteristics are consistent throughout life, and that these characteristics correspond to the crimes/crime scenes. What profilers (particularly in the FBI) offer police is drawn from their claims that they can deduce the characteristics of the offender by looking at what was done at the crime scene. That is, they believe that personality is so consistent that it shows up in the crime. This means that profilers generally don't provide the police with much practical help. And they will never be able to prove this consistency.
Why not? For one thing, many so-called manifestations of personality disposition are actually matters that vary with the situation. They are choices made because circumstances change, not matters that were formed in the first five years of life. Even if it could somehow be proven that, as advocates of IP believe, aggression is either expressive or instrumental, and that crimes reflect personality, how much could that help police? Not much, for how could anyone come any closer to identifying a killer from these ideas?
Instead of studying the lives of a particular type of offender, as well as their crimes, as the author described in all the articles on serial murderers’ lives, personality characteristics and crimes, IP researcher Gabrielle Salfati, like many serial murder researchers, separates all the crime scene actions (e.g. moving the body, shooting, forensic evidence, etc.) from one another and from the persons committing the crimes. They thereby learn little of practical or theoretical significance about the case. (Salfati has not, to the author’s knowledge, acquainted herself with serial murder cases, from birth to death.) Having separated and isolated crime scene actions, Salfati and IP researchers try to put them back together by performing a “multidimensional scaling procedure known as Smallest Space Analysis” (Salfati, 2000, p. 272), an imprecise method which is purported to show which actions are near each other in two-dimensional space. The actions are then labeled as expressive, as instrumental, or as hybrids. It is unclear how this classification is made, or how it can be done objectively. Further, the cropping up of "hybrids" contradicts the original binary assumption.
IP researchers also believe that the victim-offender interaction is one of the most important determinants of what happens in a murder, something else which cannot be observed. So they are not particularly interested in the types of cases for which police need help: multiple victim, multiple offender, and stranger-to-stranger crimes. Even professional hits, as Salfati, 2000, explains, were excluded because they did not deal with the issues of her interest! This selectiveness seems to be a bit like stacking the deck in favor of her own hypotheses. This could be why IP researchers begin their studies with samples of murders that are the easiest to solve. But, as Bandura (1973, p. 2) so clearly explains, aggression is not like other social behaviors that require all the participants to go along for its success. Nor is it a process determined by the victim, except in small ways, such as types of defensive actions the victim takes:
One can injure and destroy to self advantage regardless of whether the victim likes it or not. By aggressive behavior or dominance through physical and verbal force, individuals can obtain valued resources, change rules to fit their own wishes, gain control over and extract subservience from others, eliminate conditions that adversely effect their well-being, and remove barriers that block or delay attainment of desired goals. Thus behavior that is punishing for the victim can . . . be rewarding for the aggressor.
Comparing all these facets of aggression to the simple classifications scheme used in IP, it is clear from Canter and Salfati’s original papers that they are following the traditional, exclusive, criminological focus on the poor. They never discuss aggressors as if they could be members of the dominant establishment. Their offenders’ only instrumental aim other than sex is taking money (because, we all know, only the poor steal?)
Canter (2000, p. 8) makes the point of their criminological focus very clear. When asked by the editor of Homicide Studies for his ideas on a new research agenda, Canter said what bothered him most was the idea of the “virgin killer” (in contrast, see Ritter, 2013). By this he meant the person who had “absolutely no background indicators nor any stress factors” from which to predict a murderous future. “These people are very rare, but their existence challenges everything we know about homicide.” Then it is time to broaden the IP perspective because, as both experimental psychologists and historians know, aggression is usually the province of the elite and the strong. And the field of clinical psychiatry provides such articles as the following, which is directly related to the idea of the virgin killer.
In 1978, Cohen, Groth and Siegel (p. 31) described two types of violence. One had been “demonstrated” by Wolfgang and Ferracuti’s (1967/1982) subculture of violence, which exists in an area of “widespread social and economic decay, and pervasive asocial or antisocial values and attitudes.” It is the second type that is of significance here: “However, there are also persons involved in a life-long history of violent behavior whose environment has been benign and who have suffered no apparent stresses on survival nor any special precipitating events. Here, the factors relating to the violence appear to be internal. Here, the motivational life of the offender. . . is crucial.” They cite, for instance, a case of a white offender from a stable, middle-class family who had never been convicted of a criminal act. Here again is another tie between IP and criminology, both of which show concern over the purportedly extensive criminal background of murderers and other violent offenders. But this is an idea that was peculiar to Marvin Wolfgang (1958), who completed his study of homicide at a time when others considered murderers one-time offenders, as even Wolfgang acknowledged in the 1958 study.
Profilers need to back off so that police can learn from experience how to solve their own cases without so much outmoded and questionable assistance.