“No Expert Needed to Introduce Data Pulled From Phone at Trial”

Image: Kaylee Walstad, EDRM

[EDRM Editor’s Note: The opinions and positions are those of Michael Berman.]

In No Expert Needed to Introduce Data Pulled From Phone at Trial (bloomberglaw.com) (Oct. 13, 2023), Mr. Peter Hayes reported on  United States v. Williams, 83.F4th 994 (5th Cir. Oct. 13, 2023).  

Mr. Hayes wrote: “A police officer who introduces evidence extracted from a cellphone at trial doesn’t need to be qualified as an expert in the technology used to do so, the Fifth Circuit said Friday.”  He reported:

The police investigator in Williams’ case “explicitly disclaimed that he was offering expert testimony” at trial, [Judge] Smith said.

“All the officer did was run a computer program,” [Judge] Smith said. “He offered no technical understanding of the machine or software; he did not write the program; and he did not opine on any application of specialized knowledge,” he said.

“Without a showing of specialized knowledge, the mere use and understanding of a Cellebrite extract at trial is insufficient to require an expert,” [Judge] Smith said.

Peter Hayes, No Expert Needed to Introduce Data Pulled From Phone at Trial (bloomberglaw.com) (Oct. 13, 2023).

The case presented a matter of first impression. 84 F.4th at 995.  The court wrote:

When law enforcement uses Cellebrite to pull information from a phone and a lay juror would require no additional interpretation to understand that information, the party does not need to introduce the evidence through an expert. We affirm.

United States v. Williams, 83.F4th 994 (5th Cir. Oct. 13, 2023).  

The case involved sexual relations with, and trafficking of, a minor. The Fifth Circuit explained:

After [defendant] Williams’s arrest, the police used a Cellebrite device to copy the information off Williams’s and Doe’s mobile phones. To use the device, an investigator merely plugged each phone into it and ran the program. The program pulled out the user data—including any messages, videos, or emails sent, received, or recently deleted—along with the apps used on the phone, and provided it to the police in an accessible, easily-navigable, and readable format. Williams’s Alcatel phone, being less technologically cohesive than a Samsung or Apple phone, required an additional file system extraction to copy everything on  the device. But, beyond that step, the process and the product were the same for the two phones.

Id. at 995-96.

The defendant objected to testimony by the officer.  The Fifth Circuit wrote: “On voir dire, the police investigator disavowed any particular knowledge of Cellebrite’s technology or of any malware that may have affected the data extraction. The district court then overruled Williams’s objection, and the investigator testified to (1) his certifications as a Cellebrite Operator and a Cellebrite Physical Analyzer, (2) the data-extraction process, and (3) the evidence he obtained.”

The court explained that: 

Federal Rule of Evidence 602 permits a witness to provide fact testimony if he has personal knowledge of the matter. Accordingly, lay witnesses can testify so long as the witness does not base his or her opinion for scientific, technical or other specialized knowledge within the scope of Rule 702…. 

We find no error, much less an abuse of discretion. [Defendant] Williams claims that Cellebrite is a complex technology, ergo, the operation of Cellebrite requires specialized knowledge, and the introduction of a Cellebrite report demands qualification of a witness as an expert. But this ignores the basic realities of life. All the officer did was run a computer program. He offered no technical understanding of the machine or software; he did not write the program; and he did not opine on any application of specialized knowledge.

During trial, the investigator explained that “[a]s an operator, I purely operate the machine. I am not privy to the programming or how it extracts data.” Thus, he explicitly disclaimed that he was offering expert testimony. This is the antithesis of Rule 702’s requirement of “scientific, technical, or other specialized knowledge.” Fed. R. Evid. 702(a). Rather, the investigator knew no more than anyone else who runs a program on his computer that he did not write.

Id. at 996-97 (cleaned up; emphasis added).

The Fifth Circuit cited support from the Second, Fourth, and Ninth Circuits. Id. at 997. It wrote:

We join our sister circuits. All the investigator testified to was how he downloaded the information from the phones using Cellebrite technology. At no point did he speak to the reliability of the software, except that he double-checked some of the report by looking directly at the source material in the phones themselves. To that end, he did not state any information on how Cellebrite operated in a technical sense, nor information that was beyond the knowledge of an average cell phone user. The investigator did not “implicitly vouch for the accuracy or reliability of Cellebrite’s software,” as Williams claims. Rather, the investigator acknowledged his lack of knowledge about the software and stated that he was merely an operator. Notably, the cross-examination of the investigator did not probe the reliability of Cellebrite technology.

Without a showing of specialized knowledge, the mere use and understanding of a Cellebrite extract at trial is insufficient to require an expert.  Operating a Cellebrite device and understanding its report require knowledge in the realm of a reasonably tech-savvy lay person, regardless of the investigator’s testimony that he was a “certified” operator and analyzer.

Id. at 997-98 (emphasis added).

There was a caveat.  Notably, in footnote 1, the Fifth Circuit quoted the Seventh Circuit and added: “There are cases in which the collection of digital data would require testimony due, for example, to the sophisticated nature of the particular forensic analysis or the equipment deployed, or the technical nature of the testimony. But this is not one of those cases.”

Fed.R.Evid. 602 and Fed.R.Evid. 702 – the Rules cited in Williams – apply to civil litigation also.  Cellebrite, and many other software programs, are used in civil litigation. iTunes can extract data from iPhones and it is readable using low-cost software.  FTK Imager can be downloaded for free and a layperson can make forensic images of ESI.  X1 Social Discovery is easily operable by a layperson to download websites, social media, and more.  And, of course, Google’s download your data, Facebook’s takeout, and LinkedIn’s download your account data, as well as many other programs can be operated by a “tech-savvy lay person” who does not “speak to the reliability of the software,” nor “implicitly vouch for the accuracy or reliability” of it.[1]  As an “operator,” that layperson can “purely operate it.”[2]

[1] I do not suggest that any of the software programs are anything less than fully reliable.  I am doing no more than quoting the court’s holding that testimony showing reliability was not required for admissibility.  The Fifth Circuit decided that evidence obtained using Cellebrite – – a commercial software program – – could be admitted into evidence without testimony demonstrating its reliability.  That, of course, does not imply that it, or any other program, is less than fully reliable.

[2] See generally District of Maryland Gives Qualified Approval to Non-Forensic Downloads of Social Media Data  (Aug. 10, 2021)(“Many social media programs provide their members with a non-forensic download tool.  For example, Google TakeoutUberTwitter, and LinkedIn provide download instructions.  See C. Ball, “Preserving Social Media Content: DIY (Dec. 24, 2019).”).


  • Michael D. Berman

    Mike is the owner of E-Discovery, LLC, and of counsel at Rifkin Weiner Livingston LLC, in Baltimore. He concentrates on commercial litigation and offers mediation services. He was the primary editor of Electronically Stored Information in Maryland Courts (Md. State Bar Ass’n. 2020), and he co-edited M. Berman, C. Barton, and P. Grimm, eds., Managing E-Discovery and ESI: From Pre-Litigation Through Trial (ABA 2011), and J. Baron, R. Losey, and M. Berman, eds., Perspectives on Predictive Coding (ABA 2016). Mike has litigated a number of cases in the trial and appellate courts in Maryland. He is an Adjunct Professor at the University of Baltimore School of Law where he co-teaches a three-credit discovery workshop that focuses on e-discovery. He has lectured at the Maryland Judicial College and he chaired the Bar committee that drafted the proposed ESI Principles for the District of Maryland. He is a past: co-chair of the Federal District Court Committee of the Maryland State and Federal Bar Associations; chair of the Litigation Section Council, Maryland State Bar Association; and, co-chair of the American Bar Association Litigation Section Book Publishing Board. He graduated from the University of Maryland School of Law and is also an Army veteran. He is admitted to the Maryland bar. The opinions expressed in this blog are not necessarily those of Rifkin Weiner Livingston LLC.

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