Investigative psychology is perhaps the newest area of specialization for forensic psychologists. It focuses on identifying features of a crime and likely characteristics of its perpetrator. Investigative psychology includes broader areas, such as psychological autopsies, Geographical profiling and the polygraph (Jamel & Adler, 2005, PP. 143). Psychological autopsies—more formally called reconstructive psychological evaluations—are performed after a person has died and the cause of the death is uncertain or equivocal. The psychologist conducting the autopsy tries to reconstruct the victim’s behavior and thought processes leading up to the death (Jamel & Adler, 2005, PP. 144). This procedure is often used in cases of apparent but questionable suicide. Psychological autopsies are also used—though less frequently—in civil cases in an effort to determine whether a third party may have contributed to the death. For example, an employer may have failed to respond appropriately to signals of extreme emotional distress or threats of suicide. As yet, there is no established, standard method for conducting a psychological autopsy, and its validity has yet to be demonstrated (Jamel & Adler, 2005, PP. 145).
Geographical profiling analyzes spatial characteristics of a crime along with behavioral characteristics of offenders deduced from the crime scene to yield probabilities of a perpetrator residing in a particular location (Gudjonsson, 2003, PP. 160). Geographical profiling is used primarily to solve serial crimes, in which a pattern of offending occurs over time. It is more likely to yield positive results when combined with criminal profiling, although we must caution that the scientific status of the final remains in question (Gudjonsson, 2003, PP. 162).
Polygraph - Like profiling -is not strictly an investigative technique in the narrow sense because it is used in a wide variety of criminal and civil contexts. In law enforcement, it is used primarily in the selection of candidates for law enforcement positions and much less in criminal investigation (Nelson, 1972, PP. 225). Results from polygraph tests are not admitted into courts to be used against criminal defendants, but they have been allowed in some courts to support a defendant’s contention that he or she did not commit the crime (Nelson, 1972, PP. 225). It appears that the polygraph is also being used more extensively in counterintelligence and by federal agencies than it has been in the past. Like the other techniques, the polygraph has not garnered impressive research results with respect to reliability and validity. Nevertheless, some researchers do support its use in limited situations and when administered by highly trained polygraphers (Nelson, 1972, PP. 225).
Forensic psychology role had the most increase in value and significance in law enforcement in the last two decades in two separate sub-disciplines: police and investigative psychology. The work of the psychologist within the criminal justice system can certainly take many routes depending on the specialism of the particular psychologist. From aiding the police in their investigations, advising in the selection of police officers, fitness-for-duty evaluations, conducting psychological autopsies, Geographical profiling and the polygraph , carrying out research or imparting their own knowledge to future criminal psychologists, the work is varied and challenging.