Colorado’s Top Court Seems Reluctant To Give Judicial Blessing To ‘Reverse’ Keyword Search Warrants

Having figured out the internet is a great place to find things, cops are increasingly relying on warrants that target tech companies in hopes of finding suspects, rather than finding suspects first and working forward from there.

Thanks to the Third Party Doctrine, there’s very little expectation of privacy in what people share with the companies and services they use to interact with the internet. Thanks to sheer novelty, the new law enforcement normal has been difficult to challenge, due to the dearth of precedential case law.

The US Supreme Court has at least set a few guidelines, but they’re easy to avoid or ignore. In untested waters, the first ones to fishing for information are often able to walk away with their outsized hauls. But as warrants targeting search terms or GPS location because more commonplace, they’re seeing more challenges. And every challenge presents an opportunity for courts to adjust the contours of the Fourth Amendment to meet the connected reality the founding fathers never could have imagined.

An arson prosecution in Colorado continues, but the means and methods used by law enforcement to identify and locate the suspects are still up for judicial debate. The resulting fire claimed five lives. Multiple Denver teens were arrested, based mainly on location and search data obtained from Google, rather than searches of the teens’ houses or canvassing of the neighborhood for eyewitnesses.

The challenge of this method of obtaining what’s loosely described as “evidence” began in 2022. One of the charged teen’s defense lawyers argued this method of obtaining data violated both the US and Colorado constitutions, seeing as it forced Google to search millions of people’s search terms to provide investigators with a list of potential suspects fitting the digital description.

The government searched an ocean of intensely private data in this case, yet it lacked probable cause to search even one Google user. Instead, it demanded that Google search everyone’s Google searches in order to generate suspicion. 

Particularity is important when it comes to warrants. Searching millions to find dozens isn’t all that particular.

The challenge has since moved from the trial court to the state’s top court. Also challenged is the geofence warrant deployed by Denver PD investigators. Like the reverse keyword search, the geofence warrant resulted in millions of people being “searched.”

For reference, Google had 592 million Location History users in 2018. To conduct a geofence search, regardless of the size or shape of the area, Google must comb through the account of every Location History user.

Multiple warrants were served to Google. Google rejected some of them. The ones it complied with resulted in Google digging through its digital stash of billions of data points multiple times to find what investigators were seeking. At no time did the Denver PD have anything other than probable cause to believe Google might have the data it was seeking.

Arguments are now being made before the Colorado Supreme Court. And, at least at this early stage, it appears some state justices might be inclined to believe (if not rule) that demanding a company search everyone might not comply with historical limitations placed on warrants. (h/t FourthAmendment.com)

First, let’s compare and contrast the arguments. The defense team says what’s immediately obvious about these so-called “reverse” warrants.

“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.

Over on the other side, cops are claiming searching everybody for anything is somehow a “particular” search capable of complying with the Fourth Amendment.

“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.

Sure, the end results of these broad searches may result in something more “directed” and “targeted.” But they certainly aren’t either of those things when the warrants are served to Google. Cops don’t know who’s a suspect. They’re hoping Google can narrow down that list for them by searching everything it has on hand to determine what’s responsive to the warrant.

While the two sides don’t agree on the specifics of these searches and their constitutionality, they both seem to agree state precedent established more than 20 years ago should apply to the 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.

The defendants argue broad searches equivalent to those in the Tattered Cover case infringe on multiple rights. The state argues that it has met the requirements enacted by this decision: the “compelling need” that supersedes the constitutional infringements.

The state justices aren’t so sure the cops are right.

They discussed whether Google searches should be automatically considered protected speech that would be subject to the Tattered Cover standard, and suggested that anything other than a hard-and-fast rule would be difficult to enforce.

“The way I understand your argument, it’s not just any ordinary haystack, it’s all haystacks across the globe being searched for this one needle,” Justice Monica Marquez said to Price. “I take your point that the breadth of the haystacks being searched is the problem.”

Encouraging. But the justices also noted that Google’s compelled searches only returned matches for search terms submitted by investigators. It didn’t actually require Google to dig through every search term from every user to find a list of possible suspects.

But that’s not really an accurate description of what happens during a reverse search. Google does need to search everything everywhere all at once. That it is able to sort out what’s required by the warrant doesn’t change the way the search occurs. It’s not Google’s fault. It’s the way these warrants work. Cops are supposed to work their way forward, developing probable cause to support more intrusive searches. What they aren’t supposed to do is ask third parties to treat everyone as a suspect until their harvested data proves otherwise.

Hopefully, the court will realize flipping probable cause on its head just because it’s easier to obtain information with a few mouse clicks doesn’t mean it’s the right way to do things, even when the crime being investigated is particularly horrendous.