Court hears first-of-its-kind challenge to police’s use of Google search terms to ID murder suspects

GRAND JUNCTION — The Colorado Supreme Court on Thursday grappled with privacy and freedom of speech concerns as the justices heard a legal challenge to a controversial new law enforcement technique that Denver police used to identify the three teenagers accused of killing five people in a house fire three years ago.

The groundbreaking legal case considers for the first time in Colorado — and, attorneys said, nationally — whether police can legally issue search warrants that require Google to turn over account information for any users who searched particular keywords in a particular time frame.

Such “reverse keyword search warrants” require Google to scan through potentially billions of search histories in order to find the keywords sought by law enforcement. Attorneys challenging the warrant said during oral arguments Thursday that the massive scope amounts to an illegal search that violates Google users’ constitutional protections for free speech and against unreasonable searches. Attorneys for Denver District Attorney Beth McCann argued it is an acceptable investigative tool that doesn’t violate constitutional rights or privacy rights.

“The keyword warrant here made Google search everybody who searched for anything over the course of more than two weeks,” said Michael Price, an attorney with the National Association of Criminal Defense Lawyers who argued against the use of the warrant.

“Technology allows us to conduct a directed and targeted search for the information we are looking for,” said Katherine Hansen, senior deputy district attorney in the Denver DA’s office.

A Denver police detective relied on one such reverse keyword search warrant to identify the three teenagers now accused of setting a Green Valley Ranch house fire in August 2020 that killed five members of a single family, including a toddler and infant.

Kevin Bui, 19, Gavin Seymour, 18, and Dillon Siebert, 17, each were charged in connection with the killings. Authorities said the three teens donned masks and spread gasoline in the house before setting it ablaze just before 3 a.m. on Aug. 5, 2020, because Bui erroneously believed the person who stole his cellphone was inside the house and wanted to take revenge on the thieves.

Siebert, who was 14 at the time, has since pleaded guilty to second-degree murder and was sentenced to 10 years of detention. The cases against Bui and Seymour, who were both 16 at the time and are charged with first-degree murder, have been on hold pending the Colorado Supreme Court’s decision on the legality of the search warrant, which is the lynchpin of the case against them.

In response to the reverse keyword search warrant, Google provided police a list of accounts in which the users searched the street address for the targeted home in the 15 days prior to the fatal fire. The worldwide query of all Google users turned up 61 results, including searches conducted in Colorado and Illinois. Five accounts caught the attention of investigators and eventually led to Seymour, Bui and Siebert.

Seymour, who has not been convicted, appealed to the Colorado Supreme Court after a Denver District Court judge found that the search warrant was legal. The justices heard arguments in the case Thursday at Colorado Mesa University in Grand Junction as part of the state’s Courts in the Community program.

Seymour’s attorneys argued that the reverse keyword search warrant was overbroad, infringed on Google users’ privacy rights and free speech, and amounted to an illegal search under the Fourth Amendment. In a court filing, Seymour’s attorneys compared the search warrant to opening all bank safety deposit boxes worldwide on the hunch that one may include evidence of a crime.

“It is a repository of (Google users’) personal papers and effects — their search history and other account contents — which belong to them,” the brief reads. “A warrant to search all of Google search history records would be like making that bank search the contents of every safe deposit box, worldwide, for evidence of a crime.”

Hansen countered that the search warrant was narrow, focused and constitutional, and said that there was no invasion of privacy because no human reviewed the search histories for the many uninvolved accounts.

“Seymour would have this Court ignore the realities of what occurred in this case, and instead treat a database inquiry the same as if a Google employee opened a file for each account and conducted a visual review of all of the searches performed by that user… then repeated that ‘search’ a ‘billion’ times over,” Hansen wrote in a court filing. “…The database itself was not read, observed or visualized in a manner that would have allowed Google to see the contents of any of the searches that were conducted by Google users other than the ones that matched the keyword terms in the warrant.”

The Tattered Cover case

Both sides referenced a 2002 Colorado Supreme Court case in which Denver’s Tattered Cover bookstore refused to turn over a customer’s purchasing history to police. In that case, Thornton police found a methamphetamine lab in a trailer where four people lived, along with a Tattered Cover mailing envelope addressed to one resident and two books with instructions on drug-making. The officers served Tattered Cover with a search warrant seeking information about all books purchased by that resident in a 30-day period.

The bookstore refused to comply, and the case went to the Colorado Supreme Court, which ruled the search warrant was invalid, finding that it infringed on people’s First Amendment right to seek and receive information without government surveillance or fear of reprisal. The decision established a higher legal standard that police search warrants must meet in such cases in Colorado — law enforcement must show a compelling need for the information, consider whether there are reasonable alternative ways to investigate, and a judge must find that the need for the information outweighs any infringement on constitutional rights.

Seymour’s attorneys argued that the higher Tattered Cover standard should apply in this case and that the reverse keyword search warrant fails to meet the standard and should be ruled invalid.

“You have a right to receive information anonymously in your Google searches in the same way your book purchases are protected as expressive activities,” Price said. He said detectives could have discovered the teenagers’ identities through traditional investigative methods, like looking for surveillance footage of people buying masks or gasoline.

Hansen argued the higher Tattered Cover standard does not apply to warrants for Google searches. Colorado Attorney General Phil Weiser, in his own brief, argued that the higher standard does apply and that Denver police met the standard so the warrant should be upheld.

“Warrants seeking records of what individuals searched online may intrude on their free speech rights in ways akin to warrants seeking their book-buying records,” Weiser’s brief reads. “After all, both book buying habits and search queries can reveal intimate or sensitive details about a person’s life choices or political views.”

“Not just any ordinary haystack”