The Top Ten Errors in Forensic Reports Haven't Changed in Fifteen Years. Here's What They Look Like on Cross-Examination.

In 2010, Thomas Grisso published one of the most useful and under-cited papers in forensic report writing. He analyzed 62 forensic reports submitted to the American Board of Forensic Psychology by candidates seeking board certification. Specifically, reports the reviewing panel declined to approve for oral examination. Grisso converted the reviewers' critiques into a prescriptive list of thirty factors, then ranked the ten most frequent problems.

Reading the top ten today is uncomfortable because nothing about it feels dated. The same errors that got reports rejected in 2010 are the same errors that get reports picked apart in depositions and on cross-examination in 2026. The statutes have changed. The case law has moved. The pressures on forensic evaluators have intensified. But the specific places where forensic reports fail have stayed almost perfectly stable.

Here is what Grisso found, and, more importantly, here is what each of those findings looks like when opposing counsel gets hold of the report.

1. Opinions Without Sufficient Explanations (56%)

The most common fault in the sample. Reviewers flagged it in more than half of the reports. A clinician states a conclusion about competency, diagnosis, risk, malingering, but the report does not adequately lay out the data and the reasoning that carried them there.

In a courtroom, this is the easiest vulnerability to exploit. Opposing counsel reads the opinion section, identifies the conclusion, and asks, "Doctor, on what specific data did you base that?" If the answer requires the evaluator to assemble the reasoning in real time on the witness stand, the reasoning becomes visible as something constructed after the fact rather than something that drove the evaluation. The jury notices.

The fix is straightforward in principle and hard in practice: every important opinion needs its data and its logic laid out at the point where the opinion is offered, not buried in an earlier section and expected to speak for itself.

2. Forensic Purpose Unclear (53%)

The second most common problem. In more than half of the non-approved reports, the legal standard, legal question, or forensic purpose was not stated clearly or inaccurately.

This is the vulnerability that unravels an entire report before it is even discussed on the merits. If the evaluator cannot clearly state the legal standard the evaluation was designed to address, opposing counsel has a foundational attack: "Doctor, can you tell us the statutory definition of competency to stand trial in this jurisdiction?" Every answer from that point forward is framed against the evaluator's apparent uncertainty about the question they were retained to answer.

The remedy, state the legal standard, cite the relevant statute or case law, and briefly explain how that standard shaped the data the evaluator chose to gather, is not optional. It is the foundation on which everything else in the report stands.

3. Organization Problems (36%)

Reports that presented information in a disorganized sequence, without clear logic to the order.

Organization errors rarely lead to a direct cross-examination attack, but they do something more insidious as they create the impression of an evaluator whose thinking is unstructured. In a forum where the evaluator's analytic rigor is on trial alongside their conclusions, disorganization reads as sloppiness, and sloppiness invites deeper scrutiny.

4. Irrelevant Data or Opinions (31%)

Data or opinions included in the report that were not relevant to the forensic or clinical referral question.

This one is particularly dangerous because evaluators often include irrelevant material thinking it is helpful, adding background, adding thoroughness, adding context. In forensic work, irrelevant data is not neutral. It is a foothold. Anything in the report is fair game in cross-examination, and every sentence of irrelevant content is a sentence the evaluator will have to defend as relevant or concede was unnecessary. Neither outcome benefits the evaluation.

5. Failure to Consider Alternative Hypotheses (30%)

The report did not adequately address alternative interpretations of the data, often malingering or response style alternatives, sometimes diagnostic alternatives.

This is the trap opposing counsel sets with real precision. The question takes some version of the form, "Doctor, did you consider whether [alternative explanation] could account for this finding?" If the report did not address the alternative and the evaluator cannot explain on the stand why it was ruled out, the evaluator is now engaged in post-hoc reasoning — reasoning they did not do at the time of the evaluation, reasoning that contradicts the implicit claim that their conclusion was the result of a careful differential analysis.

Addressing alternative hypotheses in the report is not a courtesy. It is evidence that the evaluator actually conducted a differential analysis rather than settling on the first hypothesis that fit.

6. Inadequate Data (28%)

The referral question or case circumstances required additional data that was not obtained — or if it was not obtained, the report did not explain why.

The cross-examination here is devastating because it does not depend on proving the evaluator was wrong. It depends only on establishing that the evaluator did not have the information needed to be confident they were right. "Doctor, you did not review the school records. Is it possible those records contained information relevant to your conclusions?"

If the data was not obtainable, say so in the report and explain why. If the data was not requested, that is a judgment call that needs to be documented as a judgment call not left as an invisible gap.

7. Data and Interpretation Mixed (26%)

Data and interpretation frequently appearing together in the section intended to report only data.

This is a structural error that has a specific cross-examination consequence: it makes it difficult for the reader, including opposing counsel and the trier of fact, to distinguish what the evaluator observed from what the evaluator concluded. When those two things blur, every conclusion becomes contestable on the grounds that it was never a neutral observation to begin with.

The discipline of separating data from interpretation is not an academic preference. It is the architecture that allows the report's reasoning to be defended under attack.

8. Over-Reliance on a Single Source of Data (22%)

Important interpretations or opinions that rested entirely on one source, frequently the examinee's self-report, when corroborating information from multiple sources was needed.

In forensic settings, examinees often have significant incentives to present themselves in particular ways. A conclusion that rests entirely on self-report in that context is a conclusion that opposing counsel will challenge on exactly those grounds. The principle that important forensic opinions require corroboration from multiple sources is well established in the literature and well understood by attorneys who cross-examine forensic experts.

9. Language Problems (19%)

Multiple instances of jargon, biased phrases, pejorative terms, or gratuitous comments.

Language problems generally don't cost a report its conclusions, but they do cost the evaluator something harder to recover: the appearance of neutrality. A report that reads as if the evaluator had already decided what they thought of the examinee before gathering the data is a report whose conclusions are easy to reframe as advocacy.

The specific language vulnerabilities are predictable: overconfident phrasing, undefined clinical terms used around non-clinicians, evaluative language that signals bias, and gratuitous detail about the examinee's character that serves no forensic purpose. Each one is avoidable with careful review before the report leaves the evaluator's desk.

10. Improper Test Uses (15%)

Test data used in inappropriate ways when interpreted and applied to the case, or tests that were not appropriate for the case in the first place.

This is the Daubert-adjacent vulnerability. A test administered outside its validated population, interpreted in a way its empirical base does not support, or applied to a forensic question it was not designed to address becomes a methodology attack. The argument from opposing counsel is not that the evaluator is wrong — it is that the evaluator's method cannot reliably support the conclusion, which is a harder argument for the evaluator to survive than a disagreement over interpretation.

Why These Ten Errors Persist

Grisso's data is fifteen years old, and the errors he identified are not different from the errors that reviewers still identify today. This is not because forensic evaluators fail to learn. It is because the underlying conditions that produce these errors have not changed.

Forensic reports are written under time pressure. They are written by clinicians who have already spent hours interviewing the examinee, reviewing records, administering tests, and forming impressions, which means by the time the report is being drafted, the evaluator is working from a dense internal understanding that is difficult to see from the outside. The reasoning feels complete to the evaluator because the evaluator has lived with it. It does not always appear complete to a reader who is encountering it for the first time.

Most forensic evaluators also do not have a structured second review before the report leaves their hands. During training, every report was supervised. After licensure, that structural feedback disappears. The common errors in Grisso's sample are, in large part, the errors that a careful second reader would have caught.

What a Pre-Testimony Review Actually Catches

This is the problem ForensicShield was built to address.

ForensicShield is a pre-testimony quality assurance layer, the step between finishing a report and defending it in court. It analyzes completed forensic reports across methodology, language precision, diagnostic alignment, ethics, legal standards, and guidelines compliance, then produces a Court Preparation Packet that identifies where the report is most likely to be challenged and what those challenges will look like.

Every one of the ten errors in Grisso's study maps to something ForensicShield looks for:

• Opinions without explanations — the analysis checks whether each stated opinion has its reasoning chain visible in the report, and flags conclusions that appear without a supporting data path.

• Forensic purpose unclear — the analysis verifies that the legal standard is clearly stated, correctly attributed, and aligned with the jurisdiction.

• Irrelevant data or scope creep — the analysis identifies material outside the referral question that opposing counsel could use as a cross-examination foothold.

• Failure to consider alternatives — the analysis looks for hypotheses the data reasonably supports that the report did not address, including the response-style and malingering alternatives that show up most often on the stand.

• Inadequate data — the analysis identifies data gaps relative to the referral question and the report's own conclusions, and flags whether the report explains those gaps.

• Data and interpretation mixed, single-source reliance, language problems, improper test uses — each has its own dedicated analysis pass, calibrated to what opposing counsel actually exploits in cross-examination.

The purpose is not to criticize the evaluator's work. The purpose is to make visible, before testimony, the specific places where the report is most likely to be challenged — and to give the evaluator the preparation they need to defend each one.

The Honest Framing

Fifteen years after Grisso's study, the top ten errors in forensic reports are the same top ten errors. They are not the product of inexperience as these were reports from candidates applying for board certification. They are the product of writing under pressure, without structured second review, in a format that has to satisfy both clinical rigor and legal scrutiny.

The question every forensic psychologist should be able to answer, about any report they have just finished, is the one that drives everything at ForensicShield:

If this report were challenged tomorrow, where would it be vulnerable?

Answering that question used to require a trusted colleague, a lot of time, and the willingness to ask. It does not anymore.

Reference: Grisso, T. (2010). Guidance for improving forensic reports: A review of common errors. Open Access Journal of Forensic Psychology, 2, 102–115.