--- title: "Psychology Expert Was Allowed to Opine on Voluntary Adult Sex-Work Subculture" meta: "og:description": "The psychology expert was allowed to testify despite his lack of exhaustive knowledge of the sex trafficking industry" "og:title": "Psychology Expert Was Allowed to Opine on Voluntary Adult Sex-Work Subculture" author: "Expert Witness Profiler" description: "The psychology expert was allowed to testify despite his lack of exhaustive knowledge of the sex trafficking industry" --- # Psychology Expert Was Allowed to Opine on Voluntary Adult Sex-Work Subculture Posted on February 6, 2026 by Expert Witness Profiler Defendants Brandon Washington and Maria Georgianna Palm are charged with various crimes arising out of their scheme to recruit, entice, harbor, transport, provide, obtain, and maintain vulnerable women, and to perform commercial sex acts for their financial benefit via threats of force, fraud, and coercion. The United States of America filed a motion _in limine_to exclude the testimony of Defendant Brandon Washington’s expert, Dr. [Justin J. Lehmiller](https://expertwitnessprofiler.com/expert-witness/Justin-Lehmiller/1572131). The Government asked the Court to exclude the testimony of Lehmiller as an expert for several reasons: First, he is not qualified to educate the jury on the topic of sex trafficking, or commercial sex work. Second, he failed to comply with [Rule 16(b)(1)(C)(iii)](https://www.law.cornell.edu/rules/frcrmp/rule_16) by failing to identify the opinions he will offer. Third, his proposed testimony will attempt to define the law, or it is irrelevant and not likely to assist the jury in deciding the facts in this case. And fourth, it violated [Rule 403](https://www.law.cornell.edu/rules/fre/rule_403#:~:text=The%20court%20may%20exclude%20relevant,or%20needlessly%20presenting%20cumulative%20evidence.) because his proposed testimony is substantially outweighed by the danger it would confuse and mislead the jury. ## **Psychology Expert Witness** Dr. [Justin J. Lehmiller](https://expertwitnessprofiler.com/expert-witness/Justin-Lehmiller/1572131) is a social psychologist, author, and senior research fellow at the Kinsey Institute at Indiana University. Lehmiller received his Ph.D. in Social Psychology from Purdue University. He has authored books such as Tell Me What You Want: The Science of Sexual Desire and How It Can Help You Improve Your Sex Life and The Psychology of Human Sexuality (third edition published in 2023). The Psychology of Human Sexuality is a textbook that is used in college classrooms around the world. He has also published extensively in peer-reviewed journals on sexual behavior, marginalized and stigmatized relationships, casual sex, and consensual non-monogamy. [Want to know more about the challenges Justin Lehmiller has faced? Get the full details with our Challenge Study report](https://expertwitnessprofiler.com/order/add?eId=1572131&pId=3). ## **Discussion by the Court** While Lehmiller’s disclosure suffered from some deficiencies, primarily the lack of specific opinions, the Court did not find them so limiting as to warrant exclusion. The fact remains that he did identify the subject-matter topics he proposed to testify about. In essence, he provided notice of his expert opinions in summary fashion via general categorizations. Next, the Government suggested that Lehmiller’s testimony will impermissibly attempt to define the law and usurp the role of the Court by defining coercion or sex trafficking concepts. The Court will not tolerate this practice from any expert or the Government’s expert. Lehmiller will be permitted to provide testimony about the voluntary adult sex-worker subculture. He will not be permitted to define legal terms or attempt to tell the jury what the law is. Nor will he be allowed to opine on what he believes constitutes illegal coercion, or define what situations constitute “voluntary” sex work from “exploitation” or “trafficking” or attempt to redefine statutory terms. It appeared to the Court that Lehmiller’s expert disclosure was timely, and the Government has been provided with adequate notice and is not claiming surprise. Moreover, there are no allegations that the defense seeks to introduce undisclosed areas of his testimony. Moreover, the Government is free to attack Lehmiller’s qualifications or the lack thereof. It will be up to the jury to determine how much weight should be accorded to his opinions, but the remedy of outright exclusion is not warranted. Finally, the Court did not find that Rule 403 would be violated by allowing this testimony. Providing testimony to provide background, contextual testimony to assist the jury in understanding subject matter outside common experience is relevant and not prejudicial to justify exclusion. ## **Held** The Court denied the Government’s motion to exclude the testimony of Dr. Justin Lehmiller. ## **Key Takeaway** While Lehmiller’s background may be deficient in having exhaustive knowledge of the sex trafficking industry, that is not the standard for [Rule 702](https://www.law.cornell.edu/rules/fre/rule_702#:~:text=Rule%20702%20sets%20forth%20the,is%20a%20relatively%20narrow%20inquiry.) admissibility. The Court finds that while not overwhelming, when considering the totality of his education, research and training, Lehmiller’s proposed testimony meets the thresholds of relevance and reliability. Please refer to the blog previously published about this case: [Law Enforcement Expert Allowed to Opine on the Dynamics of Consensual Adult Sex Work](https://expertwitnessprofiler.com/law-enforcement-expert-allowed-to-opine-on-the-dynamics-of-consensual-adult-sex-work) ## **Case Details:** --- ## **You Might Also Like** ![Human Resources Expert Allowed to Opine on Termination](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-22T200052.311.jpg) [**Human Resources Expert Allowed to Opine on Termination**](https://expertwitnessprofiler.com/psychology-expert-was-allowed-to-opine-on-voluntary-adult-sex-work-subculture/human-resources-expert-allowed-to-opine-on-termination)![Neuropsychology Expert Not Allowed to Opine on Cognitive Decline](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-22T144728.528.jpg) [**Neuropsychology Expert Not Allowed to Opine on Cognitive Decline **](https://expertwitnessprofiler.com/psychology-expert-was-allowed-to-opine-on-voluntary-adult-sex-work-subculture/neuropsychology-expert-not-allowed-to-opine-on-cognitive-decline)![Human Factors Expert Not Allowed to Opine on the Tile](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-21T191749.960.jpg) [**Human Factors Expert Not Allowed to Opine on the Tile**](https://expertwitnessprofiler.com/psychology-expert-was-allowed-to-opine-on-voluntary-adult-sex-work-subculture/human-factors-expert-not-allowed-to-opine-on-the-tile)![Insurance Expert Not Allowed to Opine on Legal Duties](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-21T155751.487.jpg) [**Insurance Expert Not Allowed to Opine on Legal Duties**](https://expertwitnessprofiler.com/psychology-expert-was-allowed-to-opine-on-voluntary-adult-sex-work-subculture/insurance-expert-not-allowed-to-opine-on-legal-duties)![Law And Legal Expert Not Allowed to Opine on Contract Formation](https://ewp-blog.expertwitnessprofiler.org/wp-content/uploads/2026/04/blog-pic-640X480-2026-04-20T213123.718.jpg) [**Law And Legal Expert Not Allowed to Opine on Contract Formation**](https://expertwitnessprofiler.com/psychology-expert-was-allowed-to-opine-on-voluntary-adult-sex-work-subculture/law-and-legal-expert-not-allowed-to-opine-on-contract-formation)