A house fire in August 2020 in Denver killed a Senegalese family—three adults, a toddler, and an infant—sleeping inside.[1] Three more inhabitants, a man, woman, and child, escaped with their lives out of a second story window.[2] Early in their investigation, police suspected arson in this tragic case in part because a neighbor’s home-security video showed three hooded figures wearing masks and approaching the home in the middle of the night.[3] However, after two months of investigation, the police had not identified a single suspect. The next step by investigators, obtaining a “reverse warrant” from a judge to review the search history of certain Google users, initiated a legal and public policy controversy about privacy, constitutional protections, and criminal investigations.

The legal controversy was documented and ruled on by the Colorado Supreme Court in an October 2023 decision, Colorado v. Seymour.[4] The court’s decision to deny the defendant’s suppression motion was a narrow one. However, the decision is one of the first to analyze the constitutionality of reverse warrants when no suspects have been identified.

As that decision explains, investigators had no leads in the fall of 2020 but had a theory the burned home had been deliberately targeted and that arsonists had probably entered the home’s address in a Google search or on Google Maps in the days and hours leading up to the crime. Police therefore turned to a novel investigation technique: seeking a “reverse keyword warrant” from a judge. Whereas a typical warrant is obtained after identifying a suspect and describes a place where police believe evidence is located, a reverse keyword warrant is obtained before identifying a suspect. The reverse warrant describes potentially incriminating internet history—here, a search of an address related to a crime—and authorizes police to obtain from Google a list of associated users or accounts to help identify a suspect.

In this case, Google refused, consistent with its privacy policies, to provide police with the sensitive information initially requested, including names and birthdates of its users who had searched the home address at issue. However, after police narrowed their inquiry and the scope of the reverse warrant, Google provided police an anonymized list of devices, identified by device identifiers and IP addresses, associated with a search of the address within fifteen days of the fire. Google, the court said, “produced a spreadsheet of sixty-one searches made by eight accounts.”[5]

With these promising leads, the police were able to narrow their search to a handful of people and gather more evidence of a crime, including incriminating evidence and private messages found on other social media sites. Police eventually identified three suspects—teenage boys who lived in the area. Based on other evidence discovered, prosecutors alleged the teenagers had splashed gasoline on the house and lit it on fire under the mistaken belief that someone in the home had earlier stolen a phone from one of the suspects.[6]

One suspect, Seymour, argued the reverse keyword warrant was unconstitutional—that it was not adequately particularized and lacked probable cause. He made a pre-trial motion to suppress all evidence resulting from the search executed under the reverse keyword warrant. Courts generally will suppress evidence gathered under a deficient warrant in order to encourage investigators’ compliance with the U.S. and state constitutions. The trial court denied the motion to suppress, and Seymour appealed to the Colorado Supreme Court.

In its October 2023 decision, the Colorado Supreme Court noted the novelty of this legal issue—the constitutionality of reverse keyword searches apparently had not been examined by any state supreme court or federal appellate court. The court therefore declined to make a “broad proclamation about the propriety of reverse-keyword warrants” and “proceed[ed] incrementally based on the facts before [it].”[7]

Nevertheless, the Colorado Supreme Court decision was notable in several respects.

For one, the court found that Seymour had “a constitutionally protected privacy interest in his Google search history” under the state constitution.[8] Under the federal Fourth Amendment’s “third-party doctrine,” most federal courts deny that people have a protected privacy interest in information voluntarily shared with third parties; a person’s internet search sends information to a search engine operator like Google to obtain search results, so the third-party doctrine removes Fourth Amendment protection from such information. However, the Colorado Supreme Court noted it has “long rejected the third-party doctrine” because the state constitution “provides greater privacy protections than the Fourth Amendment” to the U.S. Constitution. Therefore, a search had occurred because Seymour had “a reasonable expectation of privacy in his Google search history.”[9]

The court also determined that Seymour “had a constitutionally protected possessory interest in” his Google search history under the state constitution and under the Fourth Amendment to the U.S. Constitution.[10] This meant police had also “seized” Seymour’s search history. For evidence of this possessory interest, the court noted that “Google’s licensing agreement makes clear that it does not own its users’ content. Instead, users own their Google content, which, according to testimony from a Google policy specialist, includes their search histories.” [11] Therefore, the copying of Seymour’s history by police effected a constitutional “seizure”: “the act of copying . . . meaningfully interferes with the owner’s possessory interest because it infringes on one’s rights to exclude and to control the dissemination and use of that digital data.”[12]

“In sum,” the court held, “law enforcement conducted a search of Seymour’s Google activity under the Colorado Constitution and a seizure of that information under both the Colorado Constitution and the Fourth Amendment.”[13]

This was not a warrantless search, however, so the court turned to the constitutionality of the reverse warrant. To be constitutional, a warrant must (1) describe with sufficient particularity both the place to be searched and the things to be seized and (2) demonstrate probable cause.

The court was satisfied that the reverse warrant was reasonably particular in scope: namely, “the narrow search terms, the timeframe constraints, and the fact that the initial search was anonymized all served to minimize any invasion of privacy resulting from the search.”[14]

As for probable cause, however, the court “assume[d] without deciding that the warrant lacked probable cause.”[15] The court was skeptical that investigators’ belief that arsonists would “digitally case” a property by searching the address beforehand would qualify as a “substantial basis” for the magistrate judge to issue the reverse warrant.[16]

Typically, if an invalid warrant is issued, any evidence gathered as a result of the invalid warrant is suppressed at trial. Here, however, despite treating the reverse warrant as lacking probable cause, the court declined to suppress the evidence gathered. Colorado courts recognize a “good faith” exception to the suppression of evidence when investigators are gathering evidence in an unprecedented—but impermissible—way, so long as the investigators acted reasonably. Here, the court said, the investigators had no way of knowing that an individual’s Google search history is constitutionally protected, as that issue had not been litigated before in Colorado. Therefore, police had “no reason to know [they] might have needed to demonstrate a connection between the alleged crime and Seymour’s individual Google account.”[17]

In the end, though the warrant may have been invalid, Seymour’s motion to suppress the evidence was denied in the October 2023 decision. In January 2024, Seymour pleaded guilty to second-degree murder.[18]

Two justices dissented from the majority opinion. They believed the reverse warrant was completely deficient and the motion to suppress should have been granted. The dissent said “a reverse-keyword warrant functions like a digital dragnet” since these warrants don’t identify a suspect,[19] and “[t]hey are tantamount to a high-tech version of the reviled ‘general warrants’ that first gave rise to the protections in the Fourth Amendment.”[20]

The dissent disagreed with the majority that the warrant was sufficiently particularized “with respect to the place to be searched,” that is, “Google’s entire database of a billion user accounts.”[21] The dissent also stated that “the warrant was so facially deficient that it forecloses application of the good-faith exception to the exclusionary rule.”[22] The dissent predicted “ that reverse-keyword warrants will swiftly become the investigative tool of first resort. Because, why not? It’s a tantalizingly easy shortcut to generating a list of potential suspects.”[23]

Surely other courts and lawyers will study this decision, and the dissent, for years to come. Reverse warrants for search histories and similar reverse warrants for geolocation—identifying, via GPS tracking in smartphones, the accounts of people in a designated location at a particular time—are an increasingly common tool of law enforcement. The court’s finding that Google users have a protected possessory interest in their search histories, and that law enforcement copying of that information effects a seizure, will change how modern-day investigations into digital data are conducted if other state and federal judges agree.


[1] Shelly Bradbury, A second Green Valley Ranch arson suspect is on track for plea deal, attorney says, Denver Post (Nov. 9, 2023, 4:48PM), https://www.denverpost.com/2023/11/09/green-valley-ranch-arson-denver-plea-negotiations-bui-seymour/.

[2] Lindsey Grewe & Tony Keith, Report: Teens accused in deadly arson fire that killed 5 had set fire to wrong house, KKTV (Feb. 2, 2021, 6:00PM), https://www.kktv.com/2021/02/02/2-juveniles-to-be-prosecuted-as-adults-in-deadly-colorado-arson-case-that-claimed-the-lives-of-5-people-including-2-kids/.

[3] Id.

[4] 536 P.3d 1260, 1268 (Colo. 2023).

[5] Id. at 1269.

[6] Bradbury, supra note 1.

[7] Seymour, 536 P.3d at 1268.

[8] Id. at 1267.

[9] Id. at 1270.

[10] Id. at 1267.

[11] Id. at 1273.

[12] Id.

[13] Id. at 1273-74.

[14] Id. at 1276.

[15] Id. at 1278.

[16] Id.

[17] Id. at 1280.

[18] Shelly Bradbury, 19-year-old man pleads guilty to murder in Green Valley Ranch fire that killed 5 family members, Denver7 (Jan. 19, 2024, 7:25PM), https://www.denver7.com/news/local-news/19-year-old-pleads-guilty-to-murder-in-green-valley-ranch-fire-that-killed-5-family-members.

[19] Seymour, 536 P.3d at 1281 (Márquez, J., dissenting).

[20] Id. at 1282.

[21] Id. at 1283 (emphasis in original).

[22] Id.

[23] Id.

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