When Experts Cut Corners: A Forensic Psychologist’s Perspective on Upholding Standards
In high-stakes legal matters, forensic psychological evaluations carry immense weight. Judges, juries, and attorneys rely on these assessments to help answer complex psycholegal questions—questions about criminal responsibility, competency, risk, and psychological injury. These evaluations are supposed to be grounded in objective science and best practices. But what happens when an expert cuts corners?
In a recent case, I reviewed an opposing expert’s report that relied almost entirely on an MMPI protocol clearly watermarked as invalid. No additional measures of malingering or response bias were administered. Despite the invalid data and lack of corroborating methods, the expert drew definitive conclusions about the individual’s mental health, motivation, and psychological functioning.
Unfortunately, this isn’t rare. And it’s not just poor practice, it’s dangerous.
The Role of Forensic Psychologists: Objectivity and Methodological Rigor
Forensic psychologists are not therapists. We don’t sit with someone weekly and build rapport. We don’t accept what someone says at face value. We are trained to ask, “Is this credible? Is it supported by data? Is there another explanation?” Our task is to form an opinion based on multiple converging sources of information, not to advocate for either side.
That’s why validity testing is essential. When someone undergoing an evaluation has something significant to gain or lose—a not guilty verdict, financial settlement, disability rating—it is our job to measure whether their self-reported symptoms or test responses are exaggerated, feigned, or otherwise unreliable. This doesn’t mean we assume deception. It means we assess for it, scientifically.
When Psychological Testing Is Misused
The MMPI-2-RF and MMPI-3 are widely used in forensic evaluations because they contain embedded validity scales designed to detect exaggerated or inconsistent responding. But if an MMPI profile is rendered invalid due to over-endorsement, random responding, or other patterns the test publisher provides a clear warning: do not interpret the results. Yet in the case I reviewed, the expert not only interpreted the invalid MMPI, but built their entire diagnostic and forensic opinion upon it.
No alternative measures were used to assess for exaggeration, symptom fabrication, or performance validity. No structured interviews or collateral sources were cited. Instead, the report leaned heavily on speculative psychological language that was not supported by any reliable data.
This is a serious breach of forensic standards—and it can have real consequences in court.
Why This Puts Cases at Risk
When experts ignore validity concerns or rely on flawed data, they introduce junk science into the courtroom. The report may sound authoritative, but it lacks evidentiary value. Worse, it can mislead the trier of fact, especially when the opposing attorney or court doesn’t know how to challenge the methodology.
This undermines the fairness of the process. And it’s not just an ethical issue; it can be a legal one. The Specialty Guidelines for Forensic Psychology (APA, 2013) and the APA Ethics Code (Standard 9.06) require that psychologists base their opinions on sufficient information and appropriate methods. Drawing conclusions from invalid test data is neither.
Red Flags for Attorneys to Watch For
Attorneys—particularly those unfamiliar with psychological testing—may assume that all expert reports are equally reliable. They’re not. Here are some signs that your expert (or the opposing one) may be cutting corners:
The report relies on a single test, especially self-report
No mention of validity testing
Use of psychological jargon without citing data
No review of collateral records or third-party interviews
Conclusions that seem exaggerated or disconnected from the data
If you see these red flags, it may be time to consult another expert.
Doing It Right: What a Forensic Evaluation Should Include
A properly conducted forensic psychological evaluation should include:
Multiple data sources: interview, testing, records, and collateral interviews
Built-in validity measures: such as MMPI-3 or PAI with embedded scales
Supplementary malingering assessments when exaggeration is a concern
Transparent documentation of limitations or conflicting data
Objective conclusions that reflect the totality of evidence—not just the evaluator’s impressions
Our job isn’t to tell the story the attorney wants to hear. It’s to ground the legal questions in defensible, data-driven opinions.
Final Thoughts: Why It Matters
Not all psychologists belong in court. A clinician may be skilled in therapy but completely untrained in forensic methodology. Courts don’t just need licensed professionals—they need qualified experts who understand how to separate science from speculation.
As a forensic psychologist, my role is to provide clarity in cases where mental health is in question. That clarity must come from valid data, tested methods, and transparent reasoning. When experts fail to meet that bar, they don’t just undermine the case, they undermine the integrity of the justice system.
If you’re unsure about the quality of an opposing expert report, or want to ensure your own case is built on solid psychological ground, consider a forensic consultation or second opinion review. Because when liberty, compensation, or justice is on the line, cutting corners isn’t just poor practice, it’s unacceptable.
