Daubert Hearing Procedure
A Daubert hearing is a pretrial proceeding where the trial court exercises its gatekeeping function under O.C.G.A. Section 24-7-702 to evaluate whether proposed expert testimony meets Georgia’s admissibility requirements. Following Georgia’s adoption of the Daubert standard through the new Evidence Code and its extension to criminal cases by HB 478 (2022), the trial court must determine that the expert’s testimony is based on sufficient facts or data, is the product of reliable principles and methods, and reflects a reliable application of those principles to the facts of the case.
The party opposing the expert files a motion to exclude, and the court conducts an evidentiary hearing where both sides present arguments, expert testimony, and published research regarding the expert’s qualifications, methodology, and the reliability of the proposed opinions. The proponent bears the burden of establishing admissibility by a preponderance of the evidence. The trial court’s ruling is reviewed on appeal for abuse of discretion under O.C.G.A. Section 5-6-34.
Challenging the Expert’s Qualifications
The first line of challenge targets whether the proposed expert possesses sufficient knowledge, skill, experience, training, or education to qualify as an expert in the specific field at issue. Georgia courts evaluate qualifications broadly, and an expert need not hold a specific degree or certification. However, your lawyer can effectively challenge experts whose qualifications are tangential to the specific issue about which they propose to testify. A forensic chemist qualified to identify controlled substances may not be qualified to testify about the pharmacological effects of those substances on behavior. A pathologist may not be qualified to render opinions outside their subspecialty. The challenge should demonstrate a gap between the expert’s actual training and experience and the specific opinions offered, supported by the expert’s curriculum vitae, publication record, and testimony about the scope of their expertise.
Challenging Whether the Expert’s Methods Are Reliable
The core Daubert inquiry examines whether the expert’s methodology is scientifically reliable. Georgia courts consider the non-exclusive factors from Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993): whether the theory or technique has been tested empirically, whether it has been subjected to peer review and publication, its known or potential error rate, the existence and maintenance of standards controlling its operation, and its degree of acceptance within the relevant scientific community. A skilled defense attorney will focus on the factors most damaging to the specific expert’s methodology rather than arguing all factors equally. A forensic discipline with no published error rate is vulnerable on that specific factor even if it has general acceptance. The 2016 President’s Council of Advisors on Science and Technology (PCAST) report identified several forensic disciplines that lack adequate foundational validity studies, providing your defense attorney with authoritative support for Daubert challenges.
Challenging Application to Case Facts
Even when an expert’s methodology is reliable in general, the expert must have applied it reliably to the specific facts of the case. This analytical gap challenge targets situations where the expert extrapolates beyond what the data supports, relies on insufficient factual foundation, or draws conclusions unsupported by the methodology. For example, a blood spatter expert may use a validated methodology but apply it to stains that are too degraded or too small to support the conclusions offered. A forensic accountant may use accepted financial analysis methods but apply them to incomplete records that cannot support the opinions rendered. Your defense starts with examine whether the expert’s conclusions follow logically from the data analyzed, whether the expert considered alternative explanations, and whether the expert’s reasoning contains any unjustified analytical leaps.
Forensic Disciplines Most Vulnerable to Challenge
Not all forensic disciplines carry equal scientific validation. DNA analysis and forensic toxicology are well established and rarely excluded under Daubert. Fingerprint analysis is broadly accepted but faces challenges regarding examiner subjectivity, error rates, and proficiency testing protocols. Firearm and toolmark comparison is increasingly contested because the comparison process relies on subjective pattern matching, error rates are not well established through black-box studies, and the foundational assumption that every firearm leaves unique, reproducible marks has not been empirically validated to the degree required by rigorous scientific standards. Bite mark analysis faces the most severe criticism; the PCAST report concluded that bite mark analysis does not meet the scientific standards for foundational validity. Hair microscopy, footwear comparison, and handwriting analysis occupy varying positions on the reliability spectrum.
GBI Laboratory Specific Challenges
The Georgia Bureau of Investigation Division of Forensic Sciences processes the majority of forensic evidence in Georgia criminal cases. At this stage, the focus shifts to obtain the GBI laboratory’s standard operating procedures for the relevant discipline, the specific analyst’s proficiency testing records, the laboratory’s accreditation status through organizations such as ANAB, and any corrective action reports or internal audits. Prior incidents of analyst error, protocol deviation, or contamination at the GBI laboratory are relevant to both the Daubert hearing and trial cross-examination. Your lawyer may obtain these records through discovery requests under O.C.G.A. Section 17-16-4 and open records requests under O.C.G.A. Section 50-18-70. The analyst’s complete error history and proficiency testing performance are discoverable under Brady v. Maryland, 373 U.S. 83 (1963), when they bear on the reliability of the analyst’s work.
Consequences and Preservation for Appeal
Exclusion of prosecution expert testimony under Daubert can be case-dispositive. If the state’s case depends on forensic evidence that is excluded, the remaining evidence may be insufficient to survive a motion for directed verdict under O.C.G.A. Section 17-9-1. Even an unsuccessful Daubert challenge preserves the issue for appeal and educates the jury through the questions raised during the hearing. To preserve the challenge for appellate review, your defense team must file a written motion to exclude, request a hearing, present evidence and argument at the hearing, obtain a ruling on the record, and make a continuing objection when the expert testifies at trial. Georgia appellate courts have held that a general objection to expert testimony is insufficient; the objection must specifically identify the grounds under O.C.G.A. Section 24-7-702.