Category Archives: Expert witness

Error and bias in forensic behavioral science

A crisis is brewing in scientific psychology and forensic science. This concerns the overall reliability of all psychological science (more on this later) and the quality of expert evidence and testimony in courts of law, regardless of the expert’s discipline (yes, even including the supposedly hard stuff, like DNA analysis). The consensus: alarmingly poor. This […]

Ipse Dixit, Expert witnesses, & Specialty Guidelines for Forensic Psychology

Ipse Dixit in Latin means, “he himself said it”; It is frequently encountered in expert testimony. Ipse dixit is an unsupported statement that rests solely on the authority of the speaker. I think a better translation is “because I said it…[it is true].” It is a conclusory opinion without support. Gutheil & Bursztjan (2003) articulate […]

Bias, cognitive heuristics, and forensic decision-making

The cumulative weight of 30 years of research originating in Tversky and Kaheman’s seminal 1974 description of the mental shortcuts humans use when confronting cognitive ambiguity complexity, and Kahneman’s recent masterpiece Thinking Fast, and Slow (2011, cf. Gilovich, Griffin, & Kahneman, 2002) has created a mature cognitive science of forensic decision-making. The findings are not […]

Forensic Psychology is Forensic Science.

There has been a growing awareness, some would say crisis, concerning the mediocre quality of expert forensic testimony submitted to the courts in the United States. This appears to be a function of weak methods, and a low threshold for judicial gatekeeping, despite clear mandates in Rule 702 and Daubert and progeny on the foundations […]

Professional Ethics,”partisan allegiance,” and expert witness liability

Daniel Murrie and his colleagues have produced a series of recent studies on “partisan allegiance” in forensic expert witness work (see citations below). They define partisan allegiance as the tendency for experts to bias their testimony in favor of the side that calls them. They demonstrate this through ingenious experiments with PCL-R ratings. The response […]

Thriving as a forensic psychologist

A nice article by William Foote PhD in APA’s Good Practice (Winter 2014) is worth a look for students who think they might be interested in forensic psychology. Contrasting clinical and forensic psychology, he writes, “But the field is not for everyone…Forensic psychology is also much more confrontational. You’re often in an adversarial position, with […]

Assessing Homicidal Mental States at the Time of Offense IV: The 2011 Norway Massacre: Criminal responsibility analysis using the R-CRAS.

The use of forensic assessment instruments is a distinguishing factor in the quality of forensic reports (Fuger, Acklin, Nguyen, Ignacio, & Gowensmith, 2013). In insanity determinations, the Rogers Criminal Responsibility Assessment Scales (R-CRAS, PAR, Inc.) are without peer as an aide to organizing and analyzing case data. It is a systematic coding measure which permits […]

Analysis of Competing Hypotheses (ACH) — a method for de-biasing forensic decision making

I recently attended a three day workshop on school, campus, and workplace threat assessment and became acquainted with ACH. It is a methodology developed by the CIA and is used to consider evidence when factors are complex or ambiguous. Given the many factors that can influence forensic decision making, including examiner decision thresholds, cost of […]

New variety of shark sighted in Hawaii waters

Readers may remember my post on “Swimming with Sharks” a few months back–a set of guidelines and admonishments to clinicians working in and around the Hawaii Family Court. Well, a new variety of shark has recently been sighted in Hawaii waters. These are mainland forensic psychologists who have started coming to Hawaii to sell their […]

Disclosure, denial, delay, recantation, and confirmation in CSA

Despite several years of high quality research in CSA, courts continue to hear that patterns of disclosure, denial, delay, and recantation are (or are not) dispositive of CSA. In their review of these issues in a recent special issue of Memory, London, Ceci, Wright, and Ceci (2008) draw the following conclusions: “We have argued that, […]