Tracking Device Warrants: Deadlines, Scope, and Notice

A federal tracking device warrant authorizes law enforcement to install a GPS device on a vehicle or other property and monitor its location for up to 45 days from the date the judge signs it, with installation required within 10 calendar days. The authority comes from Federal Rule of Criminal Procedure 41, and the time limits are strict: miss the installation window and the warrant expires, monitor past 45 days without an extension and the data risks suppression.¹

When Officers Need a Warrant

Two Supreme Court decisions set the baseline. In United States v. Jones (2012), the Court held that physically attaching a GPS tracker to a vehicle and monitoring its movements is a Fourth Amendment search, which means a warrant supported by probable cause is required.² In Carpenter v. United States (2018), the Court extended that protection to historical cell-site location information held by wireless carriers, ruling 5–4 that acquiring those records also qualifies as a search.³

The two cases cover different mechanics but reach the same place: location surveillance by the government generally requires judicial authorization. The procedural rules differ, which matters later in this article when cell-site records come up.

The 10-Day Installation Deadline

Rule 41(e)(2)(C) gives officers 10 calendar days from the warrant’s issuance to install the tracking device. Weekends and holidays count. If the device isn’t in place by the end of day 10, the warrant is dead and cannot be revived to justify a late installation, even if the probable cause supporting it hasn’t changed.¹

When the window closes, officers have to go back to the issuing court and apply for a new warrant. The judge reviewing that second application will reassess whether probable cause still exists, which keeps investigators from sitting on open-ended authority while a case drifts.

There is also a default rule about the time of day. Installation must occur during the daytime unless the judge expressly authorizes nighttime installation for good cause.¹ Investigators routinely ask for nighttime authorization because covert attachment is easier when the vehicle is parked and unattended, but that authorization is not automatic. If the warrant doesn’t include it, a 2 a.m. installation is vulnerable to challenge.

The 45-Day Monitoring Window

A single tracking device warrant authorizes monitoring for a maximum of 45 days. The clock starts the day the warrant is issued, not the day the device is installed.¹ If officers use the full 10 days to install, nearly a quarter of the monitoring window is already gone before any data is collected. That gives investigators a strong practical reason to install quickly.

When 45 days isn’t enough, the court can grant extensions in increments of up to 45 days each, provided the government shows good cause and the investigation is still active.¹ There is no fixed limit on the number of extensions a court can approve, but each one requires a fresh justification. Location data collected after the authorized period ends, with no extension in place, is open to suppression.

Interstate Tracking on One Warrant

A tracking device warrant issued in one federal judicial district can authorize monitoring across district and state lines. Under 18 U.S.C. § 3117, if the device is installed within the issuing court’s jurisdiction, the warrant may authorize tracking both inside and outside that jurisdiction.⁴ Rule 41 reinforces this by permitting the warrant to explicitly authorize tracking “within the district, outside the district, or both.”¹ Officers don’t need a new warrant each time the vehicle crosses a boundary.

What the Warrant Lets Officers Do

Installation is covert work, and the warrant accounts for that. Officers may enter a vehicle or go onto private property without the owner’s knowledge or consent to place the device. The standard federal tracking warrant form, AO 104, includes a provision in which the judge authorizes that surreptitious entry.⁵ Common methods include magnetic attachment to the undercarriage or hardwiring the device into the vehicle’s electrical system.

The authority to enter is limited to installing, maintaining, and removing the device. Officers cannot use the tracking warrant as a cover to search the cabin, trunk, or any storage compartment. That requires a separate search warrant with its own probable cause showing.

Maintenance Visits

Trackers run on batteries, and batteries die. The standard warrant authorizes officers to re-enter the vehicle or property during the monitoring period to maintain or replace the device, and they must document the dates and times of each visit.⁵ The same scope restrictions apply, and maintenance authority ends when the monitoring period does.

Staying Within Scope

Every action has to fit inside what the judge approved. The warrant names the specific vehicle or property, the location of installation, and the authorized times. Placing a device on a second car not covered by the warrant, or operating outside the approved time windows, gives defense counsel a direct line of attack on the admissibility of everything the device recorded.

Return and Notice After Tracking Ends

When monitoring stops, Rule 41(f)(2) imposes two deadlines, both running 10 days from the date the tracking device’s use ended.

First, the officer who executed the warrant must return it to the judge named in it. The return documents when the device was installed, how long it was active, and when monitoring stopped, along with any maintenance visits.¹⁵

Second, within those same 10 days, officers must serve a copy of the warrant on the person who was tracked or whose property was tracked.¹ The warrant itself identifies the issuing court, the authorized tracking period, and the target of surveillance, so serving a copy gives the tracked person what they need to understand what happened and to challenge the search. Missing either deadline can support a suppression motion.

When Notice Can Be Delayed

In many investigations, telling the target within 10 days would compromise the case. Under 18 U.S.C. § 3103a, a court may authorize delayed notice of up to 30 days when the government shows reasonable cause to believe immediate notification would endanger someone’s life or safety, cause flight from prosecution, result in destruction of evidence, lead to witness intimidation, or otherwise seriously jeopardize the investigation.⁶ A showing that notice would merely delay a trial is not enough.

When secrecy remains necessary after the initial 30 days, the government can seek extensions, each requiring an updated showing. Section 3103a limits extensions to 90 days or less unless the facts justify a longer period.⁶ A related provision, 18 U.S.C. § 2705, allows delayed notification of certain surveillance orders for up to 90 days per extension on similar grounds.⁷ In long-running cases, these can stack, keeping the target in the dark for months.

Cell-Site Records Follow a Different Track

Physical GPS trackers are only one way the government monitors location. Wireless carriers automatically log which cell towers a phone connects to, producing a detailed record of the owner’s movements. After Carpenter, acquiring historical cell-site location information generally requires a warrant supported by probable cause, not the lower showing that once sufficed under the Stored Communications Act.³

The ruling was deliberately narrow. The Court did not address real-time cell-site tracking or “tower dumps,” where carriers hand over data on every device connected to a particular tower during a specific window. Those questions remain open. Carpenter also preserved exigent-circumstances exceptions, so pursuit of a fleeing suspect, protection from imminent harm, or prevention of evidence destruction can still justify warrantless acquisition.³

When Officers Can Track Without a Warrant

Even after Jones, a handful of exceptions let officers install a tracker without first getting a warrant. Each is narrow, and the government carries the burden of justifying it.

Consent from the vehicle’s owner, or from someone with joint control, is sufficient on its own. No probable cause or reasonable suspicion is required under this exception.
Exigent circumstances, such as an immediate threat to life, an actively fleeing suspect, or imminent destruction of evidence, allow installation without a warrant, but probable cause is still required.
At the border and ports of entry, federal agents may install trackers on vehicles entering the country. The Department of Justice considers warrantless monitoring defensible for roughly 48 hours under this exception, with longer tracking generally calling for a warrant.

If a court later rejects the claimed exception, every piece of evidence derived from the tracking is potentially tainted. That risk is why, outside clear emergencies, investigators who want their evidence to hold up at trial get the warrant.

1
Legal Information Institute. Federal Rules of Criminal Procedure Rule 41
2
Justia. United States v. Jones, 565 U.S. 400 (2012)
3
Justia. Carpenter v. United States
4
Office of the Law Revision Counsel. 18 USC 3117 – Mobile Tracking Devices
5
United States Courts. Tracking Warrant (AO 104)
6
Office of the Law Revision Counsel. 18 USC 3103a – Additional Grounds for Issuing Warrant
7
Office of the Law Revision Counsel. 18 USC 2705 – Delayed Notice