A Daubert motion asks a federal judge to decide whether proposed expert testimony meets the admissibility requirements of Federal Rule of Evidence 702. It can seek to exclude an opinion or limit what the expert may say. The judge decides that preliminary evidence question under Rule 104(a); the motion does not itself decide whether a defendant is guilty, and an expert’s impressive credentials do not make every opinion admissible.
What must the proposed expert testimony show?
The party offering the expert must show that Rule 702’s requirements are more likely than not satisfied. The judge examines whether the witness is qualified, whether specialized knowledge will help resolve a relevant issue, whether the opinion rests on sufficient facts or data and reliable methods, and whether the expert reliably applied those methods to the facts of this case. The last step matters: a method may be sound in general but fail to support the particular conclusion offered. (Rules 702 and 104(a).)
| Question for the actual opinion | What to compare |
|---|---|
| Qualifications and fit | What expertise is needed for this opinion, and how will it help the judge or jury understand evidence or decide a disputed fact? |
| Facts and method | What records, samples, assumptions or measurements did the expert use? What method produced the opinion, and what are its limits? |
| Application | Do the steps shown in the report connect the method and the case facts to the specific conclusion the expert plans to give? |
In Daubert v. Merrell Dow Pharmaceuticals, the Supreme Court discussed flexible reliability considerations such as testing, peer review, error information and acceptance in the relevant field. Kumho Tire v. Carmichael explains that the judge’s gatekeeping role also reaches technical and other specialized expertise. Those considerations are not a rigid checklist that every type of expert must satisfy in the same way. The current Rule 702 text supplies the controlling admissibility requirements. (Rule 702.)
What can a person facing a federal charge review?
Start with the actual proposed opinion and its supporting material, rather than the label “expert.” In a federal criminal case, Criminal Rule 16 provides routes to specified government examination or test reports and written expert disclosures, subject to the rule’s conditions and applicable requests. Defense expert disclosures have separate reciprocal conditions, and the court or local rule sets disclosure timing. Rule 16 is not a guarantee of every underlying item or of an automatic pretrial hearing.
Counsel can compare the disclosure, report, actual data, method, assumptions and proposed conclusion, then identify a specific Rule 702 gap for the judge. A ruling may admit the testimony, restrict a particular opinion or exclude it; disagreement between experts alone does not promise exclusion. (Rules 702 and 104(a); Criminal Rule 16.)
Does the same rule govern a California state prosecution?
No. California state courts apply California’s expert-evidence law, including Evidence Code §720 on qualifications, §801 on the subject and basis of an opinion, and §802 on examining the reasons for it. In Sargon Enterprises v. University of Southern California, the California Supreme Court explained the judge’s gatekeeping role under those provisions, including excluding speculation or reasoning unsupported by the matter relied on, without merely choosing between competing expert views. Calling a state motion “Daubert-like” does not make federal Rule 702 the governing California rule.
If an expert opinion may affect your criminal case, keep the disclosure, report and any court order together for counsel’s review. To discuss the evidence and applicable court procedure, contact the Law Offices of David S. Chesley at (800) 755-5174.