This experiment examined the accuracy and reliability of the memory and encoding related multifaceted electroencephalographic response (MERMER) technique for detecting information related to events subjects have experienced, despite subjects' efforts to conceal that knowledge. Information obtained through interviews was used to develop stimulus sets consisting of words and phrases presented to subjects visually by computer. Sets were composed of three types of stimuli: life experience-related (Probes), stimuli the subject was asked to memorize and respond to (Targets), and irrelevant information (Irrelevants). Each set of stimuli was tested on two individuals: (1) one individual who had participated in the event in question—and thus had the relevant information stored in his/her brain, and (2) one who had not. Six subjects were tested. Electrical brain responses to the stimuli were recorded non-invasively from the scalp and analyzed. MERMERs, (memory and encoding related multifaceted electroencephalographic responses), of which the P300 is a sub-component, were used to determine whether the subject had the relevant information stored in his brain (information present) or not (information absent), thus indicating whether or not each subject had participated in the real-life event in question. Bootstrapping was used to analyze and compare the responses to the three types of stimuli. As predicted, MERMERs were elicited by Probe stimuli only in the subjects who had participated in the investigated event, by Target stimuli in all subjects, and in no case by Irrelevant stimuli. For each of the six subjects, brain MERMER testing correctly determined whether the subject had participated in and consequently knew about the event in question (information present) or had not participated (information absent). The statistical confidence for this determination was 99.9% in five cases and 90.0% in one case. The article concludes with a discussion of areas of future research and the potential for using this new technology as an investigative tool in criminal cases.

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A significant minority of threateners stalk, approach, or become violent after threatening. Violence risk and threat assessment have traditionally relied on evaluating the threatener’s behavior, disposition, and membership in violent groups. However, the identity of the threatener is often unknown, and the assessor must make an initial evaluation using only the language in the threat. By combining predictive factors and their ratios to one another, our predictive model can assess linguistic characteristics of the threat without any information about the threatener, the target, or the relationship between the two. This model assesses predatory thinking, which has a strong relationship with eventual action. The language in both single threat cases and the first threats in cases with multiple threats can be used to promptly assess the likelihood that a threatener will act, enabling assessors to effectively manage cases and mitigate harm.

The goal of this research was to identify factors that improve the accuracy of violence risk assessments made in cases involving threatening communications. Specifically, this research examined psychopathological, social, demographic, and dispositional characteristics of threateners, target/victim types and their relationship with threateners, psycholinguistic features of threatening communications, and methods of contact. The goal was to assess whether or not these variables are significantly associated with a greater likelihood that threateners would approach or harm targets. The outcome of each threat case was retrospectively determined through interviews of local, state, and federal law enforcement officers who investigated these cases. The study's database consisted of 96 cases investigated and assessed by the Federal Bureau of Investigation's National Center for the Analysis of Violent Crime. Variables were scored manually and by two computer software programs which identified threateners' cognitive and emotional states. This study examined three broad hypotheses: (1) There are social, demographic, and psychological characteristics of threateners associated with threat case outcome; (2) There are social and demographic characteristics of targets/victims associated with threat case outcome; and (3) There are language features, document features, and methods used to communicate threats associated with threat case outcome. iv The first hypothesis was not supported, since characteristics of the threatener were not found to be associated with case outcome. The second and third hypotheses were supported by the following trends: two risk-enhancing factors related to the target/victim and eight risk-enhancing and four risk-reducing factors related to the threatening communication and methods of communicating were associated with case outcome. Two variables appear to signal the presence of cognition and emotion associated with predatory violence. An equation was created that accurately predicted 70.8% of all case outcomes in this study and 93.2% of the outcomes in the low (.00-.19) and 92.9% in the high (.5-1.0) ranges of prediction scores. Some limitations of this study and future research directions are discussed, along with potential application to involuntary hospitalization (commitment) decisions and release (i.e., from psychiatric hospitals) and parole decisions.

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