Signal Lost: Mississippi Federal Court Declares Tower Dump Warrants Unconstitutional

On August 5, 2026, U.S. District Judge Carlton Reeves of the Southern District of Mississippi held that tower dump warrants are per se unconstitutional. In re Four Applications for Search Warrants Seeking Information Associated With Particular Cellular Towers A/K/A Tower-Dump Warrants, No. 3:25-CR-38, 2026 WL 2260371 (S.D. Miss. Aug. 5, 2026). Such a warrant directs a cell carrier to turn over records for every phone that connected to a given cell tower during a specified window. Reviewing a magistrate judge’s denial of two sets of warrant applications, the court did not simply find those applications deficient; it held that no tower dump warrant can satisfy the Fourth Amendment. The decision matters on two fronts: investigators have used tower dumps routinely for more than a decade, and courts rarely condemn an entire investigative technique.

Judge Reeves acknowledged that these warrants are “uniquely effective” when investigators believe the same individuals committed crimes across multiple locations, because cross-referencing data from different scenes can help identify who was present at each. But because a tower dump specifies no target phone or person, a single search can produce thousands of records, the vast majority belonging to people with no connection to any crime.

The Applications and the District Court’s Analysis

The applications remain under seal because they arise from an ongoing federal investigation into gang-related crimes spanning 14 months. In February 2025, the government sought time-and-location data from four cell providers for towers near the relevant crime scenes. A magistrate judge denied those applications as impermissible general warrants under United States v. Smith, 110 F.4th 817 (5th Cir. 2024). In June 2025, the government returned with a narrower package: six locations tied to a two-day span in 2024, 10 to 30 minutes of records per location, and only devices that connected to two or more of the towers. The magistrate judge again denied the applications on the same reasoning, and the government sought review in the district court.

The court first considered whether a tower dump is a search at all — i.e., whether individuals have a reasonable expectation of privacy in the data the government collects — and concluded that it is. The court drew on the reasoning of three decisions that it described as leaving “a trail of breadcrumbs” for how to resolve the legality of tower dump warrants: (1) Carpenter v. United States, 585 U.S. 296 (2018), which recognized a privacy interest in cell-site location information but expressly declined to address tower dumps; (2) United States v. Smith, 110 F.4th 817 (5th Cir. 2024), which held geofence warrants unconstitutional because it is the search itself — not just its results — that must be narrowly tailored; and (3) Chatrie v. United States, 609 U.S. __, 146 S. Ct. 2193 (2026), which held that geofence warrants are searches regardless of a warrant’s temporal limits.

The government argued that Smith recognized a privacy interest only in location data more precise than a tower dump provides. The court disagreed, concluding that “the inherent nature of this type of search remains corrosive to individuals’ privacy interests,” regardless of precision. The court also rejected the government’s comparison to security cameras: cameras record people out in public, while tower dumps can identify people inside buildings and other sensitive areas — data the court called “intimate and deeply revealing.”

The court then addressed the general-warrant question before reaching probable cause and particularity, invoking the Founders’ intent that “no warrant can authorize the search of everything or everyone in sight.” Smith, 110 F.4th at 836 (citation omitted). Applying Smith, the court held that tower dumps are impermissible general warrants because they identify no specific user and no precise sector or tower.

The court also found no probable cause. The government’s affidavits asserted only a fair probability that gang members had committed a series of offenses and had used cell phones to do so. They identified no specific user — only a time and place where someone may turn up. Under Smith, that showing is constitutionally insufficient: probable cause must exist as to “each phone number contained within the dump,” and nothing in the affidavits supplied it. Smith, 110 F.4th at 837 n.11. The court acknowledged that other courts, including the Eighth Circuit in United States v. James, 3 F.4th 1102, 1105 (8th Cir. 2021), have found such a showing sufficient, but it expressed “doubts that any tower dump warrant applications could be” supported by probable cause.

Particularity failed too. The court noted that the targeted areas included major highways serving thousands of drivers daily, including during rush hour, yielding by its estimate “thousands if not tens of thousands” of records. Nor did the two-or-more-locations limitation rescue the June applications. Because providers must still search every record in their possession to identify any overlap, the court held that “[p]ost facto narrowing cannot justify an unparticularized search.”

Acknowledging its ruling “may thwart certain criminal investigations,” the court concluded that the government “cannot have ‘access to an entire haystack because it may contain a needle.’”

Takeaways

Three points stand out from the decision.

First, this is one decision from a district judge — it binds no other court, not even others in the Southern District of Mississippi. Its significance lies in being one of the first published decisions to declare tower dumps per se unconstitutional rather than to police the boundaries of a particular application. Defense counsel will want to consider it in suppression motions, although the good-faith exception may temper its practical force: officers who obtained tower dump data under a warrant issued elsewhere will invoke that exception.

Second, because neither the Supreme Court nor the Fifth Circuit has considered tower dump warrants directly, and the court supplied a separate application-specific ground for denial, future litigants have room to argue that Judge Reeves’ categorical holding is dictum.

Finally, the case’s posture leaves no clear path to review. The case arose ex parte, before any warrant issued. There is no defendant, no suppression record, and no obvious final, appealable order. The government’s realistic options are mandamus or waiting for a case in which investigators actually obtained tower dump data and a defendant challenged it. District courts also remain split on whether tower dumps are searches at all, and that division may eventually give the Supreme Court a vehicle to resolve the question it reserved in Carpenter.

Courts elsewhere will now decide whether to follow Judge Reeves’ categorical approach or to keep testing tower dump warrants application by application. We at Enforcement Edge will continue to monitor developments in this space.

© Arnold & Porter Kaye Scholer LLP 2026 All Rights Reserved. This Blog post is intended to be a general summary of the law and does not constitute legal advice. You should consult with counsel to determine applicable legal requirements in a specific fact situation.