Daubert motion templates for plaintiff attorneys: the FRE 702 attack playbook
Four attack vectors, one motion-language template per vector, and three case-pattern examples drawn from common med-mal fact sets.
The 2023 amendment, briefly
On December 1, 2023, the amended Federal Rule of Evidence 702 took effect. The rule now reads (in relevant part):
A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if the proponent demonstrates to the court that it is more likely than not that: (a) the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue; (b) the testimony is based on sufficient facts or data; (c) the testimony is the product of reliable principles and methods; and (d) the expert's opinion reflects a reliable application of the principles and methods to the facts of the case.
Two things changed from the pre-2023 text. First, the Rule now makes the preponderance standard explicit: the proponent must show the admissibility requirements are met by a more-likely-than-not standard, not merely articulate a plausible theory. The Committee Note states this was needed because many courts had been misapplying the standard — effectively letting anything pass as a "jury question." Second, subsection (d) now says the opinion must reflect a reliable application of the methodology, not just use a reliable methodology in the abstract. Methodology drift at the application layer is now textually Daubert-reachable.
Both changes help plaintiffs attacking defense experts. Below are four attack vectors, each tied to one prong of the rule, with motion-language you can adapt.
The original cases, for grounding
The doctrinal anchors are Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993) and Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999). Daubert established that Rule 702 imposes a gatekeeping obligation on the trial court for scientific expert testimony and listed the non-exhaustive reliability factors (testability, peer review, known error rate, acceptance in the relevant scientific community). Kumho Tire extended that gatekeeping function to all expert testimony, not just scientific testimony — which is how it reaches medical causation, life-care planning, accident reconstruction, and the rest of the expert ecosystem.
Every Daubert motion should cite both cases and the current Rule 702 text. Beyond that, grounding facts and methodology in the record is what wins the motion.
The four attack vectors
Prong (a) · Qualification
Attack 1: The expert isn't qualified for this opinion
Qualification is specialty- and opinion-specific, not credential-general. An emergency medicine physician may be qualified to opine on ED triage but not on interpretation of a pulmonary embolism CT protocol; a general surgeon may opine on surgical technique but not on neurosurgical causation. The question is whether the expert's specific knowledge, skill, experience, training, or education supports the opinion being offered.
Use this attack when the defense expert's CV is broad but the opinion is narrow and specialized, or when the expert's practice and publication history don't overlap with the issue.
MOTION EXCERPT — QUALIFICATION CHALLENGE
Dr. [Name] is not qualified under Federal Rule of Evidence 702(a) to offer
the opinion disclosed in [Report at p. __]. While Dr. [Name] is board-certified
in [General Specialty], the opinion offered concerns [Specific Subspecialty
Issue], which falls outside Dr. [Name]'s specialty training, clinical
practice, and publication record.
Specifically: (1) Dr. [Name]'s CV discloses no residency, fellowship, or
board certification in [Subspecialty]; (2) Dr. [Name]'s deposition confirmed
that [he/she] has not [performed the procedure / interpreted the study /
treated the condition] in [ __ years / clinical practice]; and (3) Dr. [Name]
has authored no peer-reviewed publications on the specific subject of the
proffered opinion.
Rule 702(a) requires that the expert's specialized knowledge "help the
trier of fact." Where the expert lacks training, experience, and scholarship
in the precise subject of the opinion, the knowledge offered is not
specialized knowledge under the Rule. Plaintiff respectfully requests that
Dr. [Name]'s testimony be limited to [scope supported by qualifications]
and excluded as to [the specific subspecialty opinion].
Prong (c) · Reliable methodology
Attack 2: The methodology isn't reliable — or wasn't the methodology used
This is the classic Daubert methodology challenge. The question under prong (c) is whether the methodology is reliable, and under prong (d) whether the expert actually applied that methodology. The two prongs are distinct but usually overlap.
The strongest methodology challenges come from: (1) deviation from published clinical practice guidelines the expert's own specialty recognizes; (2) use of a methodology not documented in the expert's report; (3) reliance on conference abstracts, letters to the editor, or the expert's own unpublished case series in lieu of peer-reviewed original research; (4) "ipse dixit" reasoning — a naked opinion with no stated method.
MOTION EXCERPT — RELIABLE METHODOLOGY CHALLENGE
Dr. [Name]'s opinion on [issue] must be excluded under Rule 702(c) because
it is not the product of reliable principles and methods. Three failures
appear on the face of [his/her] report and deposition testimony:
First, Dr. [Name] does not identify the principles and methods [he/she]
applied. The report states the conclusion ("in my opinion, the standard
of care was met") without identifying the method by which that conclusion
was reached — no stated differential, no stated guideline, no stated
peer-reviewed source. Rule 702 does not permit ipse dixit opinion.
Second, to the extent Dr. [Name] relies on [method], that method has not
been subjected to peer review, has no known error rate, and is not
generally accepted in the relevant scientific community. See Daubert v.
Merrell Dow Pharmaceuticals, 509 U.S. 579, 593–94 (1993).
Third, Dr. [Name]'s opinion conflicts with published clinical guidelines
from [American College of __ / Specialty Society], which Dr. [Name]
[has published in / cites approvingly in other contexts]. Dr. [Name]
provides no explanation for the departure.
Under the 2023 amendment, the proponent must demonstrate by a preponderance
that the methodology is reliable. That showing has not been made.
Prong (b) · Sufficient facts or data
Attack 3: The expert didn't have sufficient data
Prong (b) is underused by plaintiff attorneys and tends to be quietly effective. The question is whether the expert reviewed enough case-specific facts to ground the opinion. Red flags:
The expert reviewed only a subset of the medical records (the defense-selected subset)
The expert didn't review the deposition testimony of treating providers
The expert didn't review critical imaging, lab results, or EMR audit trails
The expert's file production shows a materials list that doesn't match the report's assertions
The expert admitted in depo to "not having seen" specific records the opinion turns on
MOTION EXCERPT — SUFFICIENT DATA CHALLENGE
The opinion of Dr. [Name] is not based on sufficient facts or data under
Rule 702(b). Dr. [Name]'s materials list, disclosed in [response to Request
for Production No. __], includes [X] pages of records. The complete medical
file in this case comprises [Y] pages. Dr. [Name] did not review:
• [specific record: e.g., the ED triage documentation from 0431]
• [specific record: e.g., the radiology department's preliminary
CT PE protocol read at 0712]
• [specific record: e.g., the EMR audit trail showing chart edits
after the patient's decompensation]
Each of these records is directly relevant to the opinion offered. In
deposition, Dr. [Name] acknowledged [he/she] had not reviewed [each record]
(Dep. [date] at [page:line]). An expert opinion on [standard of care /
causation] that excludes [central clinical evidence] is not grounded in
sufficient facts under Rule 702(b).
Prong (d) · Reliable application
Attack 4: Methodology fine, application broken
This is the prong the 2023 amendment strengthened. Even if the methodology is reliable in the abstract, the expert must apply it reliably to the facts of this case. Common application failures:
The expert cites a clinical guideline but the guideline's criteria don't match the patient's presentation
The expert performs a differential diagnosis but fails to explain why alternative diagnoses were ruled out
The expert's causation analysis skips steps of their own stated framework
The expert relies on a study population that doesn't match the plaintiff's clinical profile (different age, comorbidities, severity)
MOTION EXCERPT — RELIABLE APPLICATION CHALLENGE
Even assuming Dr. [Name]'s stated methodology is reliable, Rule 702(d) as
amended in 2023 requires that the expert's opinion "reflects a reliable
application of the principles and methods to the facts of the case."
Dr. [Name]'s application fails this requirement.
Dr. [Name] claims to have applied [methodology: e.g., the Wells criteria
for pulmonary embolism probability]. The methodology requires assessment
of [criteria 1, 2, 3, ...]. The record shows, and Dr. [Name]'s deposition
confirms, that Dr. [Name] did not perform this assessment for [element __]:
[Dep. at __:__]: "Q. Did you assess [criterion]? A. I did not."
The omission is not a harmless departure; [criterion] is dispositive of
the probability scoring under the methodology Dr. [Name] invokes. An
opinion that selectively applies part of a multi-factor methodology, and
omits the part that would have pointed to a different conclusion, does
not "reflect a reliable application" of the methodology under Rule 702(d).
Pairing note: Attack 4 (application) pairs powerfully with Attack 3 (data). If the expert skipped records and skipped steps of their own methodology, you're attacking both the inputs and the process. Brief both; the court doesn't have to pick.
Three case-pattern examples
Below are three fact patterns drawn from common med-mal scenarios. Each shows how the four attack vectors get combined in a real motion. Names and specifics are illustrative — no actual case citations are included for the fact patterns themselves (only Daubert and Kumho Tire, which are the doctrinal anchors).
Example 1: Missed pulmonary embolism
Fact pattern: A 52-year-old presented to the ED at 0431 with pleuritic chest pain, dyspnea, and a recent long-haul flight. CT PE protocol was delayed; the preliminary read flagged a filling defect at 0712; the treating physician was not notified until 1045; the patient decompensated at 1120. The defense retains an emergency medicine physician who opines the ED triage was appropriate and causation is speculative.
Attack stacking:
Prong (b): The defense expert's materials list did not include the radiology PACS audit log showing the 0712 preliminary read timestamp or the EMR order-communication log for the 1045 notification gap.
Prong (c): The defense expert's report does not state whether the Wells criteria were applied, whether the PERC rule was considered, or which published risk-stratification methodology grounds the "appropriate triage" opinion.
Prong (d): To the extent the report invokes the Wells criteria (in deposition, the expert said "I used Wells"), the scoring excludes the recent-travel and immobilization element — which, if included, would have moved the Wells score into moderate-probability territory requiring further workup.
Example 2: Birth injury · shoulder dystocia / brachial plexus
Fact pattern: A delivery with documented shoulder dystocia produced a permanent Erb's palsy. The defense retains an OB-GYN who opines the dystocia was managed within the standard of care and the injury was the result of maternal propulsive forces rather than provider traction.
Attack stacking:
Prong (a): Limited — the OB-GYN is qualified. Skip this attack.
Prong (c): The "maternal forces" causation theory is contested in the current peer-reviewed literature; the defense expert's report does not acknowledge the opposing body of evidence or explain why it is rejected. Methodology silent on the dispute is Rule 702(c)-vulnerable.
Prong (b): The defense expert did not review the fetal heart rate strip in its entirety, the delivery note from the attending, or the deposition testimony of the delivering nurse — each of whom documents provider response times and traction technique.
Prong (d): The expert's causation analysis does not perform the differential step of ruling out provider traction; the report assumes maternal forces rather than differentially eliminating alternatives.
Example 3: Surgical never-event (retained foreign body)
Fact pattern: A laparotomy resulted in a retained surgical sponge discovered two months later on a CT scan for persistent abdominal pain, requiring a second surgery. The defense retains a general surgeon who opines the surgical count was performed appropriately and the retention was a "known, acceptable risk."
Attack stacking:
Prong (c): Retained surgical items are on the National Quality Forum's list of serious reportable events — the "never event" category — and current AORN guidelines mandate specific counting and reconciliation procedures. The "known, acceptable risk" framing contradicts the methodology the relevant specialty society has adopted.
Prong (d): Even if the expert invokes AORN guidelines, the application must show reliable use of the counting reconciliation protocol. The OR nursing records show an unreconciled count; the expert's report does not address this documented deviation.
Prong (b): The expert did not review the OR nursing notes or the surgical counts documentation — the central documents for a retained-item case.
Procedural notes
Timing. Check your local rules and the scheduling order. Many federal courts set a Daubert deadline tied to the close of expert discovery; missing it can forfeit the motion.
Deposition foundation. The strongest Daubert motions are built on the expert's own depo admissions. Before filing, review the depo transcript and cite to specific page:line locations.
Hearing requests. Some courts require a Daubert hearing; some rule on the papers. Know your judge's practice.
Scope vs. exclusion. A "limit the scope" alternative request is often more winnable than full exclusion and can still achieve the practical goal. Ask for both.
State-court versions. Adapt the rule citations to your state's evidence rule. The attack structure maps across Daubert-adopting states; the labels differ.
What a tool can do, and what it can't
Motion drafting is judgment-heavy work. A tool cannot tell you whether a specific expert's testimony is outcome-determinative in your case, whether your judge is receptive to Daubert motions, or whether a particular qualification gap is worth litigating. Those calls are yours.
What a tool can do is accelerate the mechanical input to the motion — the part where you read the expert's report and deposition transcript and extract the specific factual hooks that map to each prong. Deposition Prep Brief v2 takes the expert's report and CV and produces an "FRE 702 attack script" output that flags:
Qualification gaps (prong a): Mismatches between the CV's specialty/subspecialty and the opinion's subject, flagged with the specific CV lines.
Methodology gaps (prong c): Places where the report makes an assertion without stating a method, cites non-peer-reviewed sources, or deviates from recognized specialty-society guidelines.
Data gaps (prong b): Records in the case file that the expert's materials list does not include.
Application gaps (prong d): Where the report invokes a methodology but skips elements of it, based on a comparison to the methodology's published structure.
You still write the motion. You still pick which attacks to brief. You still verify every citation against the record and the Rule. The tool just spares you the two hours of tab-juggling between the expert's report, your case file, and the specialty guidelines — so you can spend that time on the argument.
Scope note: The motion-language templates above are starting points. Every Daubert motion is case-specific, jurisdiction-specific, and judge-specific. Treat these as structural scaffolding, not drop-in briefs.
Want the Rule 702 attack script for a specific opposing expert?
Feed the report and CV to Deposition Prep Brief v2 — get the four-prong attack surface mapped to specific report lines in about a minute. 14-day trial; no credit card.
Questions or disagreements on the attack structure? Email [email protected].
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