CAAF: The methodology of a search doesn’t have to be the best to still be reasonable

A flashing incident on a Marine base in December 2018 led to a search authorization of defendant’s cell phone. The images on the phone were first sorted by size instead of date, and that led to accidentally discovering an apparent child pornography image. The searcher stopped and consulted superiors. A separate search authorization was sought for child pornography which essentially appeared in plain view. It was not unreasonable to conduct the search as it was. Maybe it could have been done better otherwise, but that does not make it unreasonable. United States v. Shields, 2023 CAAF LEXIS 270 (C.A.A.F. Apr. 28, 2023):

We reiterate that as “‘always under the Fourth Amendment, the standard is reasonableness.'” Richards, 76 M.J. at 369 (quoting United States v. Hill, 459 F.3d 966, 974 (9th Cir. 2006)). And when it comes to cell phones and computers, although one search method may be objectively “better” than another, a search method is not unreasonable simply because it is not optimal. Here, the examiner was not rummaging through Appellant’s phone, even though the defense expert pointed to a different—and perhaps even better—way to conduct the search.

After the examiner unsuccessfully searched the iPhone’s location data, he appropriately determined he needed to broaden his search. See, e.g., United States v. Loera, 923 F.3d 907, 920 (10th Cir. 2019) (“The reasonableness of a search evolves as the search progresses and as the searching officer learns more about the files on the device that he or she is searching.”).

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This brings us to what may appear to be the circuitous nature of the examiner’s search. If the examiner knew the specific date to search—December 23, 2018—then why didn’t he first filter by date and then sort by size? Indeed, it was feasible for him to do so. But again, based on that fact alone we cannot conclude that the examiner’s actions here amounted to the “general exploratory rummaging” that the Fourth Amendment is designed to prevent. Richards, 76 M.J. at 369 (internal quotation marks omitted) (quoting United States v. Carey, 172 F.3d 1268, 1272 (10th Cir. 1999)).

It may be difficult for an individual lacking firsthand experience with Cellebrite or other digital forensic software (such as a military judge, perhaps) to have an informed opinion on the reasonableness of an examiner’s methodology. Thus, it was permissible for the military judge in this case to rely on expert testimony to assist him in assessing this important issue. See M.R.E. 702(a) (providing that an expert witness may provide testimony if it “will help the trier of fact to understand the evidence or to determine a fact in issue”). Here, the military judge recognized the forensic examiner as an expert in digital forensic examinations, and Appellant does not challenge that finding on appeal. Nonetheless, we acknowledge that the defense expert concluded that the forensic examiner “employed poor forensic search techniques” and that the search should have been conducted according to the procedures outlined in the defense expert’s report. But at bottom, the examiner and the defense expert simply disagreed on the best methodology for searching Appellant’s phone.