ISHI On-Demand: Expert Witness Testimony Skills for Forensic DNA Analysts
Coming Soon!
Forensic DNA analysts are trained extensively in scientific methodology, quality assurance, and technical interpretation. However, the courtroom presents a different challenge: communicating complex science clearly, accurately, and objectively under scrutiny.
This ISHI On-Demand module examines expert witness testimony through multiple lenses — including lived experience, prosecution, laboratory leadership, education, and cross-examination strategy. Rather than focusing on scripted responses or litigation tactics, the module emphasizes the professional responsibilities, communication skills, and preparation habits that support scientifically sound and defensible testimony.
The module reinforces that testimony is not a performance, but a professional responsibility. It highlights that analysts serve as educators in the courtroom, and that credibility depends not only on technical accuracy, but also on clarity, composure, and integrity.
This module is designed to help forensic DNA analysts and laboratory leaders strengthen courtroom readiness while maintaining scientific rigor, ethical standards, and public trust.
Featured speakers include:
- Jeffrey Deskovic – Attorney, Exoneree, Founder, The Jeffrey Deskovic Foundation for Justice
- Craig O’Connor – Director, Department of Forensic Biology, NYC Office of Chief Medical Examiner
- Susan Horan – DNA Specialist, Kings County District Attorney’s Office
- Diva Casas – Assistant State Attorney, West Palm Beach State Attorney’s Office
- Kelly Elkins – Professor, Towson University
- Alyse Margetts – Casework Supervisor, Palm Beach County Sheriff’s Office
- Rachel Singer – Executive in Charge of Forensics, Brooklyn District Attorney’s Office
- Rachel Oefelein – Chief Scientific Officer & Laboratory Director, DNA Labs International
- Forensic Leadership Alliance Panel:
o Ray Wickenheiser – Retired Director, NY State Police Crime Lab System
o Julie Sikorsky – Forensic Biology Manager, Palm Beach Sheriff’s Office
o John Collins – Former Lab Director & Author
o Pamela Marshall – Director, Wecht Institute at Duquesne University
Total Video Time: 3 hours 35 minutes
Module-Level Learning Objectives
After engaging with this ISHI On-Demand module, participants will be able to:
- Describe the role of the forensic DNA analyst as an objective scientific witness, distinct from prosecutorial or defense advocacy.
- Identify common challenges analysts face in court
- Apply practical strategies for maintaining composure under cross-examination
- Recognize and avoid common pitfalls in testimony
- Develop approaches for communicating complex DNA concepts in clear, layperson-accessible language without overstating certainty or minimizing limitations.
- Describe how preparation — including case file review, pretrial meetings with attorneys, practice exercises, mock trials, and transcript review — strengthens both courtroom performance and scientific credibility.
- Understand the importance of acknowledging limitations, including issues related to transfer, timing, mixture interpretation boundaries, and the distinction between source-level and activity-level conclusions.
- Explain how lab leadership can build a culture of continuous improvement in testimony through mentoring, peer discussion, structured feedback, mock exercises, and ongoing skill reinforcement.
- Reflect on the broader stakes of forensic testimony, including its potential impact on case outcomes, public trust, and the prevention of wrongful convictions.
Video 1: Wrongfully Convicted, Rightfully Exonerated: Jeffrey Deskovic’s Journey to Advocacy
Speaker:
Jeffrey Deskovic (Attorney, Exoneree, Founder, The Jeffrey Deskovic Foundation for Justice)
Description:
This plenary presentation from ISHI 2025 establishes the human and legal stakes of forensic testimony through the firsthand account of a wrongful conviction and eventual exoneration. Drawing on his personal experience, Jeffrey Deskovic describes how evidence was interpreted, how testimony influenced juror perception, and how scientific findings can be misunderstood or misapplied in court. The presentation frames expert testimony not as a procedural requirement, but as a responsibility with significant real-world consequences. It underscores the importance of objectivity, clarity, and adherence to scientific boundaries when presenting forensic conclusions.
Video 2: Jeffrey Deskovic’s Story – Lessons for Forensic Analysts
Speaker:
Jeffrey Deskovic (Attorney, Exoneree, Founder, The Jeffrey Deskovic Foundation for Justice)
Description:
Building on the plenary session, this interview explores in greater depth the role forensic testimony played in Deskovic’s case and the broader patterns he has observed in wrongful convictions. The discussion examines the distinction between science and advocacy, the importance of communicating limitations clearly, and the responsibility analysts carry when jurors rely heavily on expert witnesses. The segment also addresses supervision, documentation, transparency, and the need for ethical awareness in both laboratory practice and courtroom presentation. Rather than offering legal strategy, the conversation focuses on what forensic scientists and lab leaders can control: preparation, clarity, and fidelity to the science.
Video 3: Preparing for Court
Speakers:
Craig O’Connor (NYC Office of Chief Medical Examiner), Susan Horan (Kings County District Attorney’s Office)
Description:
This segment approaches testimony preparation from both laboratory leadership and prosecutorial perspectives. Craig O’Connor discusses expectations for analysts on the stand, the importance of aligning testimony with accreditation and quality assurance standards, and the role of structured preparation, mock exercises, and transcript review. Susan Horan offers insight from within a prosecutor’s office, highlighting common courtroom challenges analysts may not anticipate and emphasizing the value of communication between labs and attorneys prior to trial. Together, the speakers reinforce that effective testimony requires both technical mastery and deliberate preparation.
Video 4: Courtroom Fundamentals
Speaker:
Diva Casas (West Palm Beach State Attorney’s Office)
Description:
From a prosecutor’s perspective, this segment focuses on courtroom demeanor, credibility, and practical fundamentals of testimony. Diva Casas discusses the importance of preparation, professional presence, and clear communication when presenting scientific evidence to a jury. The conversation addresses common avoidable mistakes, the dynamics of direct and cross-examination, and techniques for maintaining composure under pressure. The emphasis remains on clarity, professionalism, and responsiveness without drifting into advocacy or overstatement.
Video 5: Communicating Complex Science Clearly
Speakers:
Kelly Elkins (Towson University), Alyse Margetts (Palm Beach County Sheriff’s Office)
Description:
This segment explores the communication challenges inherent in explaining complex DNA concepts to lay audiences. Kelly Elkins discusses the pedagogical approaches used in academic training to help students translate technical terminology into accessible language, including the use of analogies and structured presentations. Alyse Margetts describes laboratory-based strategies for preparing analysts to speak confidently about their work, including low-stakes practice exercises, mock questioning, and peer discussion. Together, the speakers emphasize that courtroom communication is a skill developed through repetition, feedback, and intentional practice, rather than an innate trait.
Video 6: Handling Cross-Examination
Speakers:
Rachel Singer (Brooklyn District Attorney’s Office), Rachel Oefelein (DNA Labs International)
Description:
This segment addresses the realities of cross-examination from both prosecutorial and laboratory leadership perspectives. Rachel Singer explains common defense objectives during cross, including highlighting limitations, narrowing answers, and challenging interpretation boundaries. Rachel Oefelein reflects on the experience of testifying under pressure and offers practical strategies for maintaining composure, including listening carefully to questions, avoiding compound answers, requesting clarification when necessary, and correcting the record if needed. The discussion emphasizes that remaining calm, objective, and focused on the science supports credibility, even in adversarial settings.
Video 7: Leadership & Continuous Improvement
Speakers:
Ray Wickenheiser, (Retired, NY State Police Crime Lab System), Julie Sikorsky (Palm Beach Sheriff’s Office), John Collins (Former Lab Director & Author), Pamela Marshall (Wecht Institute at Duquesne University)
Description:
This segment focuses on the role of laboratory leadership in cultivating long-term courtroom readiness. The panel discusses structured training programs, mock trial exercises, peer feedback systems, mentorship, and cultural reinforcement of ethical testimony practices. Emphasis is placed on viewing testimony as a professional competency that benefits from ongoing practice rather than a one-time qualification. The discussion also explores how leaders can provide constructive feedback after testimony, encourage continuous learning, and foster a culture where preparation and reflection are normalized.
Video 8: Parting Advice
Description:
In this final segment, contributors offer concise reflections drawn from their experience in laboratories, courtrooms, and leadership roles. Their closing thoughts reinforce themes of preparation, humility, professionalism, composure, and scientific integrity. The segment serves as a practical reminder that testimony is both a technical and human endeavor requiring ongoing attention and deliberate development.