United States v. Jimenez-Chaidez

The court’s reasoning

The panel restated that expert testimony is properly admitted when it rests on a reliable foundation and is relevant to the task at hand, and that district courts have wide discretion on reliability but cannot avoid making the determination. On plain-error review the panel found no error, reasoning that it is well known that cellphones store some location data. The dissent stressed the accuracy variables in cellphone geolocation and the need to establish the foundational facts underlying the data.

From the opinion

“The district court did not plainly err in admitting the location data from Ramos's phone.”

Grounds argued

This ruling turned on 2 of the eight arguments that recur across the docket. Each is defined the same way on every entry, so the same ground can be followed across rulings that reached opposite results.

Tool reliability

Whether the software or hardware used — an imaging tool, a carving engine, an extraction platform — produces accurate results, and whether the examiner can say how that is known. Courts rarely require a tool to be validated from first principles, but they do expect the examiner to know its limits.

Fit to the issue

Whether the opinion helps decide a fact actually in issue. Testimony can be entirely reliable and still be excluded because it answers a question the case does not ask.

Practice note

Rulings on the same grounds

One ruling is not a rule. These are the other entries in the docket argued on the same grounds, most-cited first — including the ones that came out the other way, which are the ones worth reading before relying on this entry for anything.

• The Daubert Docket

  All 55 rulings, filterable by ground, outcome and court, with the distribution across the three outcomes reported up front.

• Daubert and digital evidence

  The argument this docket is the evidence for: why an opinion stated one level too strongly is an admissibility problem under Rule 702(d).

• Daubert Exposure Check

  Twelve questions about an expert's methodology, mapped to the failure modes these rulings keep finding, with the remediation for each gap.

• Daubert or Frye?

  Which reliability test your forum applies — settle that before relying on a ruling from another jurisdiction.

← BACK TO THE DAUBERT DOCKET

Attorney advertising / expert services. Each entry summarises a decision as it appeared in the opinion linked from that entry, on the day the entry was written. Decisions are reversed, vacated, superseded, and distinguished, and the text of Federal Rule of Evidence 702 was itself amended effective 1 December 2023 — check the current status and subsequent history of any ruling before relying on it. Nothing here is legal advice, none of it is a prediction about how any court will rule, and it is not a substitute for the rules, standing orders and case law of your own forum.