In United States v. Thorne, No. 23-3054 (D.C. Cir. 2026), the United States Court of Appeals for the D.C. Circuit highlighted Fourth Amendment considerations that arise when officers use GPS-ping data and cell-site simulator technology to locate a wanted suspect, as well as the application of the good-faith exception when officers reasonably rely on a warrant in good faith.
This case involved two different types of warrants. First, a GPS-ping warrant “orders a cellular telephone company to affirmatively create evidence about the whereabouts of a particular cellular telephone” by sending a “ping” to the cell phone, in which the carrier then collects GPS coordinates using satellite data to triangulate the phone’s approximate location within about 500–1,000 meters. The carrier then sends the results to law enforcement. Next, a cell-site-simulator warrant allows officers to precisely pinpoint a phone’s location as it continuously analyzes signal strength and directional information in real time. The cell-site simulator mimics a cell tower with “an especially strong signal,” which “induces nearby cell phones to connect and reveal their direction relative to the device.” Initially, the simulator collects unique identifying numbers from all devices nearby but is eventually narrowed to focus on the targeted cell phone.
Summary of the Facts
Arising out of a 2018 joint investigation conducted by several law enforcement agencies, the FBI, ATF, and D.C. Metropolitan Police investigated Omar Elbakkoush, suspected of drug and firearms trafficking in the D.C., Maryland, and Virginia area. Using surveillance and controlled purchases, officers identified Linwood Thorne as a key heroin supplier in the operation. From the investigation in D.C. and Maryland, officers determined that Thorne likely lived with his girlfriend, Kelli Davis-Johnson, at her home located in Northeast D.C. on Foote Street. Officers also discovered that Thorne owned an auto body shop, “Dou Perfect,” in Clinton, Maryland.
In December 2018, officers executed search warrants at both properties. First, at the D.C. residence, officers discovered over fifty pounds of marijuana in duffle bags, as well as about forty-four kilograms of heroin and fentanyl located inside several locked tool chests. This search also produced drug paraphernalia like sifters, blenders, digital scales, and small baggies. A search of the master bedroom uncovered six guns. One of the guns was lawfully registered to his girlfriend, Davis-Johnson. However, the additional five guns, 3 Glock pistols, 1 Ruger pistol, and 1 Taurus pistol, were unregistered and concealed in bags. Officers then recovered a receipt, mail, and a hotel membership card, with Thorne’s name printed on each, from the same master bedroom. Officers then searched Thorne’s auto body shop in Maryland, where they discovered Thorne’s passport, his birth certificate, his credit card, and a lease to the property in his name. A grand jury in the District of Columbia indicted Thorne on multiple criminal charges, and a warrant was issued for his arrest.
In executing an arrest warrant for Thorne, officers attempted to locate him by tracking two cell phones associated with him. The first phone had a Maryland 301 area code. Officers learned of that number through a pen register installed on Elbakkoush’s phone, traced it to Thorne’s Maryland auto body shop, and later confirmed through Thorne’s girlfriend that the number belonged to him. The second phone had a D.C. 202 area code. Officers learned that Thorne was associated with that number after a Maryland-based attorney, Mr. Bates, and another attorney contacted authorities and unsuccessfully attempted to negotiate Thorne’s voluntary surrender. For each of Thorne’s phone numbers, officers applied for and obtained two types of cell-phone location warrants, a GPS-ping warrant and a cell-site-simulator warrant, from a D.C. magistrate judge.
Officers used the warrants to determine the location of Thorne’s D.C. cell phone but not his Maryland phone, as the Maryland phone had been turned off at the relevant time. GPS-ping data from the D.C.-area-code phone placed the device in Baltimore. Officers then utilized a cell-site simulator in Maryland, which narrowed the phone’s location to an apartment on Linden Avenue in Baltimore. Officers arrested Thorne at that apartment and seized four cell phones, two belonging to Thorne and two belonging to James Hutchings, Thorne’s drug-trafficking partner. Officers searched the contents of the cell phones after obtaining a warrant to do so, and text message evidence recovered from Hutchings’s phone confirmed Thorne’s ownership of the unregistered firearms found at Foote Street.
Thorne moved to suppress evidence obtained under the cell-site-simulator warrant, arguing the warrant violated Federal Rule of Criminal Procedure 41(b) because the phone that officers were targeting was likely in Maryland, not D.C., when the warrant was issued. The district court denied suppression, reasoning that the good-faith exception applied and that officers’ reliance on the warrant was objectively reasonable. After trial, a jury convicted Thorne on most counts, and he appealed. Although Thorne’s challenge centered on Rule 41(b) of the Federal Rules of Criminal Procedure, this legal update considers the court’s application of the good-faith exception to examine why the court concluded that suppression was not warranted, even assuming the warrant was issued in error.
Legal Concepts
In Katz v. United States, 389 U.S. 347, 357 (1967), the Supreme Court explained that warrantless searches are per se unreasonable, subject only to a few well-established exceptions. United States v. Green, 149 F.4th 733, 743 (D.C. Cir. 2025). If officers acquire evidence in a manner that is found to be in violation of the Fourth Amendment, such evidence is subject to the exclusionary rule, which requires that the evidence be suppressed and bars a prosecutor from using such evidence against a criminal defendant to establish guilt. Mapp v. Ohio, 367 U.S. 643, 654 (1961). However, in United States v. Leon, 468 U.S. 897, 920 (1984), the Supreme Court carved out a good-faith exception to this rule, recognizing that, “When an officer relies in good faith on a warrant issued by a judicial officer, even if that warrant is later found to be deficient, evidence discovered as a result of the unlawful search or seizure will not be suppressed.”
United States Court of Appeals for the D.C. Circuit
When the case reached the Circuit, the court affirmed the denial of Thorne’s motion to suppress, holding that the good-faith exception applies to warrants issued in violation of Rule 41(b). The court explained, “even if the magistrate judge erred in issuing the cell-site-simulator warrant, suppression of the fruits of that warrant is unjustified because the investigating officers reasonably relied on the warrant in good faith.” United States v. Leon, 468 U.S. 897, 920 (1984); United States v. Magruder, 126 F.4th 671, 679 (D.C. Cir. 2025).
The opinion acknowledged that this outcome is consistent with the decisions of every other court of appeals that has considered the issue, noting that “eleven of our sister circuits have extended the good faith exception to this very context.” The Court reiterated the “good faith exception” standard, which holds that evidence should be suppressed when officers do not act in good faith, i.e., “when the police exhibit deliberate, reckless, or grossly negligent disregard for Fourth Amendment rights.” The Court held that officers acted in good-faith reliance on the warrant that authorized them to use a cell-site simulator to ascertain the location of Thorne’s cell phone, which led to Thorne’s arrest and the discovery of incriminating evidence.
In its reasoning, the court emphasized that there was little more the officers could have done to demonstrate their good-faith belief that the phone was within D.C. when the warrant was issued. The court pointed to the affidavit language to highlight the good-faith efforts by officers. The affidavit stated that, as of December 19, 2018, the day officers executed search warrants at both properties, Thorne lived at 4215 Foote Street Northeast in Washington, D.C. The affidavit further explained that, after speaking with another resident of the house, Thorne’s girlfriend, officers confirmed that Thorne still used the target cellular device as his own phone. When officers applied for the warrant for the target phone seven days later, on December 26, they relied on that recent information. Because any error here would likely be attributable to the judge, suppression of the evidence would not deter police misconduct when the officers are essentially blameless. The court held that the evidence obtained through the cell-site-simulator warrant remained admissible.