#14: The Truckee Street Murders - A Fatal Mistake at 2:40 A.M.

Full Episode Transcript

At 2:38am on Wednesday, August 5th, 2020, Amadou Sow was woken by the shrill beeping of smoke alarms. At first, it wasn’t clear what was happening. The sound was disorienting, but it didn’t stop. Seconds later, he registered the smell—burnt plastic, something chemical. Then came the heat.

The 46-year-old sat upright in bed. His home on Truckee Street, in the Green Valley Ranch neighborhood of Denver, Colorado, was on fire.

He jumped up and ran for the door. But as soon as he opened it, a wave of black smoke pushed through the frame like a living thing. The air was thick and hot. He couldn’t breathe. He slammed the door shut and backed away, coughing. There was no time to think.

He turned to the window. Behind him, flames were beginning to eat into the hallway. Sow punched the screen out with his fist and jumped from the second floor. The landing shattered the bones in his left foot. Somewhere behind him, inside the house, his wife and daughter were still trapped.

Hawa Ka had woken up seconds after her husband. Their 10-year-old daughter, Adama, was asleep next to her. Ka pulled her from bed and dragged her to the window. She forced the child through the opening and yelled for Sow to catch her. He reached out but missed. Adama hit the ground hard—but miraculously stood up, crying but unhurt.

Ka followed. Her fall was worse. She landed flat on her back. A sickening crack followed. Her spine broke in two places. She screamed in agony. Sow barely heard her.

His eyes were fixed on the window of their son’s room. Oumar Sow was 22 years old. His bedroom was quiet. No move ment. No noise. Sow picked up a rock and hurled it at the glass. It bounced off. He stepped back, terrified. Then he looked over at the driveway.

Oumar’s car wasn’t there.

He wasn’t home. He was likely at work, covering a night shift at 7-Eleven. That meant he was safe. For a moment, the panic in Sow’s chest eased.

But there were still others inside the house.

It wasn’t just the four of them. Nine people lived at 5312 Truckee Street—three generations of a Senegalese-American family, many of them recent immigrants, packed into a rental home in a quiet suburban street. Some were upstairs. Some were on the ground floor. By now, the fire had reached every part of the structure.

The sky above the neighborhood glowed orange. Flames shot from the roof. Windows shattered outward. Neighbors stepped out of their homes and froze. Someone called 911. By the time emergency services arrived, the house was nearly gone.

The fire had taken hold in under five minutes. What started as a deep sleep for everyone inside became a nightmare. Some had made it out.

Others wouldn’t.

In the Rocky Mountains of Colorado, far from the Atlantic shores of West Africa, a resilient and tightly bonded community of Senegalese immigrants quietly laid down roots in the 1990s. It was then that the first wave of immigrants from Senegal began to establish themselves in the region, drawn initially to towns scattered across the Rocky Mountains. These early arrivals found employment in hospitality and retail industries, taking positions that required long hours and steady hands. Among them was Djibril Diol. Some of these new residents were refugees, forced to leave Senegal as a border war with Mauritania in the 1990s tore through their homeland. After navigating the asylum process and securing their green cards, many returned to their roots to bring their families over to join them. Denver’s comparatively affordable housing, when measured against the soaring costs of the mountain towns, drew many Senegalese families into its fold.

The community’s foundations were laid in these small mountain towns. Senegalese workers, often separated from family, took low-wage jobs in hospitality and retail, sending money home and waiting—sometimes years—for legal residency to bring loved ones over. Once green cards were secured, many families relocated to Denver, drawn by cheaper housing and proximity to others from the diaspora. The urban environment offered community, resources, and a shared sense of survival in a country where many felt invisible.

It was within this context that the Senegalese Association of Colorado (SAC) was born. In 1997, Samba Kane, a community leader, called the first meeting at his home. The goal was to unify, to create an anchor point for a growing population whose needs—legal, cultural, social—were specific and urgent. By 1999, the association had gained official recognition from the state, with documentation signed by members Samba Ndiaye, Baidy Ly, and Mansour Ba.

SAC provided more than just cultural programming; it became a de facto social service organization. When members were detained, SAC coordinated bailouts. When someone fell ill or couldn’t afford rent, SAC mobilized. When newcomers arrived, SAC offered guidance on navigating housing, jobs, school registration, and immigration paperwork. It also preserved culture through language classes in Wolof, holiday celebrations, and events that centered Senegalese dance, fashion, and cuisine.

By 2020, Denver’s Senegalese population was estimated at around 2,000. Though numerically small, it was a deeply intertwined community. Hospitality and retail work had given way to more stable professions—some became engineers, accountants, or taxi drivers. Community spaces were shared. Traditions, including communal meals eaten by hand, were practiced openly in neighborhoods across the city.

Among those who had emerged as a central figure was Papa Dia, a Senegalese immigrant who arrived in Denver in 1998. His own journey was emblematic of the immigrant experience: learning English, working at a bookstore, and eventually becoming a bank teller. It was there that he encountered a steady stream of African immigrants struggling to understand banking systems. Fluent in Wolof and French, Dia helped them navigate account openings, loans, and signatures on forms they couldn’t read. That work evolved into the African Leadership Group (ALG), a broader nonprofit serving African immigrants. Under Dia’s leadership, ALG became not just a service provider, but a convener of cultural life—hosting events, offering education, and connecting the African diaspora in Colorado with one another and with local authorities.

Within this tight-knit community, the Diol family occupied a central and cherished place.

Djibril Diol, 29, had graduated with a degree in civil engineering from Colorado State University. His aspirations were firmly rooted in the notion of service — he dreamed of using his technical knowledge to improve infrastructure in the rural regions of Senegal. Ousman Ba, a close friend, recalled him as a joyful man, a natural leader, and above all, a brother. His wife, Adja Diol, 23, shared a vision for the future. She planned to return to school, with dreams of becoming a nurse. Djibril’s sister, Hassan Diol, 25, had similar ambitions, hoping to one day complete her nursing studies. Their lives revolved around family, work, and faith, marked by a quiet devotion to their community and mosque.

Amadou Sow, a 46-year-old Senegalese immigrant, had purchased the four-bedroom property at 5312 Truckee Street in the Green Valley Ranch neighborhood in 2018. The neighborhood was relatively new and somewhat isolated, but for Sow, who typically worked night shifts at Walmart, the house served as a place of refuge.

Amadou Sow shared the home with his family, including his wife, Hawa Ka, and their 10-year-old daughter, Adama. Amadou and Hawa also had a 22-year-old son named Oumar, who also lived in the house. However, on the night the fire broke out, Oumar was not at home; his father realized his car was not in the driveway and believed he was working his night shift at a 7-Eleven.

Not long after Amadou Sow's family moved into the Truckee Street residence, the family of his friend, Djibril Diol, joined them, establishing a shared living arrangement prior to the fire. It was from this home, shared by the Sow and Diol families, that Amadou Sow, Hawa Ka, and their daughter Adama were forced to make a desperate escape in the early morning hours of the fire.

In total, nine people called the house home .

In the early hours of August 5, 2020, an unthinkable tragedy unfolded. At 5312 Truckee Street, a two-story home housing nine people, a fire erupted. Within minutes, flames engulfed the building. Djibril Diol, his wife Adja, and their 22-month-old daughter Khadija perished in the fire. Djibril’s sister Hassan and her six-month-old daughter Hawa Beye also lost their lives. The devastating reach of the fire left little hope of survival for those trapped inside.

A neighbor awoke to the piercing sound of screams and rushed to their window, only to witness the house already overtaken by flames. Firefighters arrived moments later, but the inferno was too advanced. Police officers were among the first responders on the scene and made valiant efforts to enter the building. They were forced back by the overwhelming heat and flames. The fire had already consumed the structure, leaving only its skeletal frame blackened and smoldering.

Amadou Sow, his wife Hawa Ka, and their 10-year-old daughter Adama made the split-second decision to jump. The escape came at a cost. Amadou Sow’s left foot was fractured upon impact, and Hawa Ka suffered severe injuries, her spine shattered in two places. Against all odds, Adama landed on her hands and feet and emerged unscathed.

The investigation into the fire that claimed the lives of five members of the Diol family began in the early hours of August 5, 2020. The scene that confronted the first responders was one of devastation. Denver Police Officer Gordon King was the first officer to arrive, spotting the fire at approximately 2:40 a.m. near East 51st Avenue and North Tower Road. Flames erupted from the lower floor of the residence at 5312 Truckee Street. Smoke thickened in the night air, and the structure was fully engulfed. The fire burned with such ferocity that it consumed the home’s frame in less than ten minutes. Officers arriving on the scene attempted to breach the building to rescue the trapped occupants, but the intensity of the heat and smoke forced them back. Fire crews arriving shortly afterward were able to enter once the blaze was partially subdued. The bodies of Djibril Diol, Adja Diol, Khadija Diol, Hassan Diol, and Hawa Beye were recovered from the first floor near the front door.

The case was assigned to Detective Neil Baker, a seasoned homicide investigator with nearly three decades of experience in Denver law enforcement. Known for his deliberate methods, Baker was in his fifties, his appearance marked by reading glasses, thinning hair, and a rosy complexion. Assisting him was Detective Ernest Sandoval, nearly fifteen years Baker’s junior and recently transferred to the homicide unit. Sandoval had expected that his new assignment might involve routine procedures — writing reports and attending autopsies — but the scope and gravity of this case became apparent almost immediately.

Support came from the federal level as well. ATF agent Mark Sonnendecker, specializing in digital forensics, joined the investigation. Sonnendecker, slim and soft-spoken, was often compared to Bill Nye in appearance and demeanor, according to ‘Wired’ in an article on the case. His role was to analyze digital evidence, a task that would prove crucial in the long months ahead.

The community’s anguish deepened in the weeks that followed. Grief gave way to fear and a sense of vulnerability. Members of the Senegalese and broader African immigrant community feared that the fire might have been a hate crime, given that the victims were Black Muslim immigrants. Community leaders expressed concerns that the investigation might not be receiving the attention it deserved, raising questions about whether the victims’ identities influenced the pace of the investigation. Many Senegalese immigrants responded by installing security cameras at their homes, a quiet but pointed measure of self-protection.

Detectives like Baker and Sandoval felt the weight of community expectations. The pressure was immediate and unrelenting. The tragedy had left a deep scar, not only on those directly affected but on the broader Denver community. Maria Mendoza, a neighbor of the Diol family, described being awakened by urgent, panicked cries in the night: “Get the baby out! Get the baby out!” These words echoed through the darkness, a devastating reminder of the final moments inside 5312 Truckee Street.

The community was gripped by shock and fear. Many residents feared that the fire might have been a targeted hate crime. The victims were Black, Muslim, and immigrants — a fact that fueled suspicion and heightened anxiety.

The loss reverberated far beyond Denver. Senegal’s president and consul general monitored the case closely. Denver’s Mayor Michael Hancock offered his condolences and pledged that the city would uncover the truth. A Denver Police detective, reflecting the sentiments of many, called the fire one of the most heinous crimes in the city’s history. Denver’s District Attorney echoed this, describing the act as “a horrible, horrible, horrific crime.”

The Diol family, who had quietly and diligently built their lives in Denver, were gone. Amadou Beye, husband of Hassan and father to baby Hawa, was in Senegal at the time of the fire, waiting for a visa. He never met his daughter.

In the wake of the devastation, the community gathered in mourning. This was not just the loss of a family — it was a rupture in the heart of a community that had, for over two decades, found ways to build and rebuild. The fire at 5312 Truckee Street was not simply a fire; it was a deliberate act of violence that left scars both visible and invisible. The Senegalese community in Denver, united in grief, faced a long road toward healing.

Leaders within the African immigrant community voiced fears that others might also be targeted. Many families in the Senegalese community installed security cameras at their homes, seeking some measure of safety amid the uncertainty. At the same time, there was a rising concern that the case might not be receiving the full attention it demanded, given the identities of the victims.

The pressure on the investigative team was immense. Community grief and fear translated into public outcry for answers. Detective Baker would later describe the period as “a devastating time for Denver, for this community.” Denver District Attorney Beth McCann characterized the case as “horrible, horrible, horrific,” reflecting the weight of loss and the expectations placed on law enforcement. The Denver Police Department issued orders for detectives like Baker and Sandoval to focus solely on this investigation, halting the intake of new cases. Every resource available was marshaled toward finding those responsible.

Yet, in those early months, the investigation moved forward through a haze of grief and frustration, a grim and methodical process of seeking clarity where little was initially evident. The quiet devastation of the Diol family’s home marked not just a physical loss but a deep scar across a close-knit community, its trust shaken and its resilience tested.

Especially when suspicions of Arson arose in the early stages of police investigations.

In the days and weeks that followed, investigators faced a seemingly impenetrable wall. Hundreds of tips came in, including some from psychics, but none yielded actionable leads. The case stagnated. Baker later reflected on the early stages of the investigation, admitting disbelief at the sheer volume of evidence they would eventually uncover. In the beginning, however, that evidence was elusive. Denver Police Department leadership instructed the homicide team to dedicate their full attention to the case. Detectives were told not to take on any new cases, evidencing the gravity and urgency of the situation.

The crime scene itself was chaotic, and immediate suspects were absent. The first solid lead emerged from a neighbor, Noe Reza Jr., who shared surveillance footage from his home. His cameras captured three figures in hoodies and full-face masks approaching the Diol residence at 2:26 a.m. on the morning of the fire. Approximately twelve minutes later, the same figures were seen sprinting away, moments before flames erupted from the house. The video depicted one of the suspects possibly carrying a gasoline can. It also captured the group’s vehicle—a dark-colored sedan—making erratic turns as it entered and left the neighborhood. However, the video was too grainy to identify either the suspects or the precise model of the vehicle.

Detectives and agents began their investigation with interviews of the victims’ friends and family. They scrutinized text messages and financial records, seeking any thread that might suggest motive or potential conflict. Djibril Diol and his family had lived quiet, devout lives, attending mosque and focusing on work and family. There were no apparent signs of enmity or personal vendettas.

Detectives Baker and Sandoval returned to the surveillance footage. In clips gathered from doorbell cameras around Green Valley Ranch, a dark sedan could be seen making a series of erratic turns as it entered the neighborhood. The same vehicle was later recorded swerving across streets and mounting curbs as it fled. The image quality, however, was too poor to identify a make or model. The car remained unidentified.

With little else to go on, the investigators turned to digital records. They applied for what are known as tower dump warrants—court orders requiring cell phone providers to hand over information about all devices that connected to nearby towers at the time of the fire. They also issued geofence warrants to Google, requesting data from any devices that had reported their location near 5312 Truckee Street in the early hours of August 5. At the time, many Android phones—and even iPhones with Google apps installed—logged this kind of data by default.

The response from Google and the carriers came back quickly, and it was overwhelming. Thousands of phone numbers. The data was handed off to Mark Sonnendecker, an agent with the Bureau of Alcohol, Tobacco, Firearms and Explosives. Sonnendecker worked digital forensics. He had a reserved demeanor and a methodical approach. He started by focusing on one provider—T-Mobile. In his experience, the company often accounted for a disproportionate number of users in past investigations.

Sifting through T-Mobile’s logs, Sonnendecker found that 1,471 devices had connected to towers within a one-mile radius of the fire during the window of interest. Using signal-return software—tools that analyze the timing of signals between devices and towers—he narrowed the list down to the hundred phones closest to the house.

Toward the end of August, police returned to Green Valley Ranch with a cell-site simulator—equipment that mimics a phone tower and collects identifying data from nearby phones. Over the course of one evening, it recorded 723 device IDs. Sonnendecker compared those against his earlier list. Sixty-seven devices appeared on both. They were likely local residents. That left 33 phones unaccounted for—T-Mobile subscribers whose presence in the area during the fire couldn’t be easily explained.

Investigators considered bringing those 33 individuals in for questioning. But with no solid leads, they held off. There was concern that any public action might alert the suspects and give them time to disappear. For the time being, the list was set aside.

By mid-September, momentum was beginning to slow. Hundreds of tips had come in through Crime Stoppers—some credible, others far-fetched. The detectives followed leads as far as Iowa, and questioned a group in the town of Gypsum who had been found with firearms, narcotics, and black masks. They interviewed members of the Senegalese community in Silverthorne. Nothing stuck. Baker later said: “We got pretty hopeful here and there, but it just kind of fizzled out.”

Public attention didn’t wane. That summer, protests across the U.S. had brought national focus to cases involving Black victims. In Denver, a petition demanding that law enforcement prioritize the arson investigation gathered nearly 25,000 signatures. The pressure on Baker and Sandoval increased. The department told them to set aside all other cases.

At a meeting in September, the pair asked colleagues for any suggestions—anything they hadn’t yet tried. A detective raised a question: had anyone looked into whether the suspects had searched the house’s address online before the fire?

It was a simple idea. But it opened up a new possibility. Perhaps Google had a record of who had searched for the address.

They contacted Sonnendecker and the deputy district attorney overseeing the case, Cathee Hansen. None of them had ever requested a search history like that before. But after checking legal records, they discovered that similar warrants had been issued in a handful of previous cases—bombings in Austin, a fraud investigation in Minnesota, a trafficking case in Wisconsin, and a federal case involving an associate of musician R. Kelly. The details of those cases had mostly been sealed. But the precedent was there.

Hansen and Sandoval drafted the warrant from scratch. They asked for the names, birth dates, and physical addresses of any Google users who had searched for 5312 Truckee Street—or close variations—in the two weeks leading up to the fire.

Google rejected the request.

According to court documents, the company follows a multi-step process for reverse keyword search warrants. First, they provide anonymized data. Only if law enforcement identifies matches as relevant will Google release identifying information. The initial Denver warrant had asked for too much too soon.

It took another failed submission and two calls with Google’s legal team before investigators found language the company would accept.

The breakthrough came on the day before Thanksgiving. Sonnendecker received a list of 61 unique devices—along with associated IP addresses—that had searched for the Truckee Street address prior to the fire. Of those, five were located in Colorado. Three had searched the address multiple times, including for floor plans and interior photos.

Baker later described the moment as a turning point.

In early December, investigators served another warrant to Google, this time asking for subscriber information linked to the five Colorado IP addresses. One belonged to a delivery service. Another was tied to a relative of the Diol family. The remaining three were reviewed carefully.

One stood out. The name matched an individual from Sonnendecker’s earlier list of 33 unexplained T-Mobile users.

The surname was Bui.

Detective Baker recalled it was like “a door they’d never noticed suddenly flung open.”

Kevin Bui was sixteen years old in the summer of 2020. The son of Vietnamese immigrants, he grew up in Colorado, where his family had initially faced the struggles common to many newcomers—tight finances, long hours, few guarantees. But over time, things improved. His father’s business began to thrive, and the family eventually settled into a spacious home, a marker of how far they had come.

Despite the appearance of stability, there were tensions simmering beneath the surface. Bui was intelligent—academically successful despite a reported dislike for school—and physically capable, involved in swimming and football. But outside the classroom and sports field, his interests took a darker turn.

Bui was close with his older sister, Tanya. Together, they sold marijuana and fentanyl. He also began making plans to commit online credit card fraud and had started stockpiling weapons. At some point, a line was crossed. Bui started talking about revenge.

In late July 2020, Bui arranged to purchase a gun in central Denver. The deal didn’t go as planned. Instead of receiving the weapon, he was robbed by the sellers. His shoes, his money, and his iPhone were taken. The humiliation of the encounter hit him hard.

Using the “Find My Phone” app on his iPad, Bui tried to locate his stolen phone. The signal pinged to an address: 5312 Truckee Street, in the Green Valley Ranch neighborhood.

He believed the people inside the house were responsible for what had happened to him. He wanted to get even.

Messages uncovered later would show the trajectory of Bui’s thinking. On August 1, he texted one of his friends, Gavin Seymour, writing: “hashtag possibly ruin our futures and burn his house down.” Another message sent shortly after the robbery read: “They’re gonna get theirs like I got mine.”

Investigators would describe Bui as the mastermind of what followed. He enlisted Seymour and another friend, Dillon Siebert. Bui and Seymour were 16, and Siebert was 14.

Bui began researching the house at 5312 Truckee Street. He looked it up thirteen times in the week following the robbery. He used real estate websites like Zillow to view the interior layout of the home. He was preparing for something.

On August 4, two nights before the fire, Bui and Siebert were captured on surveillance footage shopping at a Party City store. They bought black theatrical masks. Later that evening, they reportedly stopped for dinner at a nearby Wendy’s.

In the early hours of August 5, the plan was set into motion.

Bui, Seymour, and Siebert got into Bui’s Toyota Camry. They stopped at a gas station, where they filled a red canister with gasoline. Then they made the half-hour drive to Green Valley Ranch.

At 2:26 a.m., a neighbor’s surveillance camera captured three masked individuals in dark hoodies approaching the home on Truckee Street. The footage showed them moving around the backyard. They appeared to be carrying a gas can.

According to court documents, the trio entered the home through an unlocked back door. Gasoline was poured as an accelerant. Then the fire was lit.

Twelve minutes later, the same camera showed the three figures running away from the house. Flames erupted within two minutes of their exit. The group fled the area in a dark sedan. Video surveillance recorded the car making several erratic turns while leaving the neighborhood.

In the aftermath, Bui and Seymour left town. They went on a camping trip. Later that morning, around 10 a.m., Bui conducted an online search for news about the fire. It wasn’t until the next day, when media outlets began reporting the deaths of five people inside the home, that Bui came to understand what he had done.

They had set the fire at the wrong address.

The phone linked to the critical Google searches belonged to Bui’s sister, but investigators quickly traced it to Kevin Bui himself. Further social media scans connected Bui to the two other teenagers—Gavin Seymour and Dillon Siebert—who also appeared in cell phone records placing them near the fire scene. All three were from Lakewood, a city miles away, with no apparent ties to the victims.

The “Find My Phone” app, relying on imprecise location data, wrongly indicated that the phone was at 5312 Truckee Street. None of the Diol family had any connection to Bui, the stolen phone, or the robbery.

Digital evidence provided the backbone for the case. Bui’s Google searches revealed multiple queries for the Truckee Street address and even the house’s interior layout. Cell phone records placed the three suspects near the crime scene at the time of the fire. Surveillance footage from a nearby Party City showed them purchasing masks resembling those worn in the neighbor’s video just hours before the blaze. Additional video captured Bui’s Toyota Camry in the same shopping complex parking lot.

Months after the fire, in January 2021, Kevin Bui, Gavin Seymour, and Dillon Siebert were arrested. Bui confessed, admitting that he set the fire because he believed his stolen phone was in the house.

The community, left grieving and searching for answers, finally learned the twisted story behind the tragedy. Through a combination of digital records and relentless investigation, authorities had unmasked the teenagers responsible for one of Denver’s most shocking crimes.

According to a Wired article the case wound its way through the Colorado court system for a year and a half. It took nearly twelve months before a judge ruled that Dillon Siebert, who was 14 at the time of the incident, would be charged as a juvenile. His co-defendants, Kevin Bui and Gavin Seymour, both 16 at the time, would stand trial as adults. A conviction could mean life in prison.

In June 2022, as prosecutors prepared to move forward, Seymour’s legal team filed a motion that threatened to halt the case altogether. They asked the court to suppress the evidence obtained through a reverse keyword search warrant served to Google.

By then, nearly two years had passed since five members of the Diol family were killed inside their home. For those left behind—relatives, friends, members of the local West African community—the grief remained sharp. Many had not yet returned to normal routines. Now, detectives had to inform them that the entire case could be jeopardized. If the court found the warrant unconstitutional, the primary evidence linking the teens to the crime might be inadmissible.

Seymour’s lawyers described the warrant as a form of mass surveillance. In their view, police had instructed Google to search through the private histories of billions without specific suspicion—what they called a “digital dragnet.” The Fourth Amendment, they argued, prohibited such general searches. Law enforcement, they said, must show probable cause to investigate a particular person before seeking access to their data. Seymour had not been a suspect prior to the search results.

The judge disagreed. He found that the request, though broad in scope, did not breach constitutional limits. Comparing it to a search for “a needle in a haystack,” the court ruled that the act of querying a database, even a vast one, did not constitute an impermissible intrusion if the parameters were reasonably defined.

The legal issue appeared resolved. But in January 2023, Seymour’s attorneys announced that the Colorado Supreme Court would hear an appeal. It was the first time a state’s highest court agreed to examine the constitutionality of a reverse keyword warrant. The decision, while binding only in Colorado, would likely affect law enforcement practices elsewhere. Observers also noted that the outcome might influence how federal authorities view such warrants going forward.

The question before the court extended beyond the scope of the case itself. It touched on broader concerns about privacy, surveillance, and the evolving relationship between individuals and the technologies they rely on. “Even a single query can reveal deeply private facts about a person,” Seymour’s attorneys wrote. “Search history is a window into what people wonder about—and it is some of the most private data that exists.”

In May 2023, the Colorado Supreme Court heard oral arguments. Seymour’s attorney likened keyword searches to geofence warrants, which some courts had recently begun to reject. A federal circuit court would later declare geofence warrants unconstitutional under the Fourth Amendment, citing the lack of particularized suspicion.

Denver prosecutor Cathee Hansen, who had helped draft the original warrant, defended the method. She compared it to querying financial institutions for suspicious transactions. In her view, no individual privacy was violated. The warrant simply asked for a list of users whose search terms matched specified criteria, and Google had returned that information without identifying anyone beyond the results.

The judges pressed Hansen on potential applications of such warrants. Justice Richard Gabriel raised the possibility of future misuse. Could, he asked, a state where abortion was illegal request a list of users who had searched for abortion clinics in Colorado? Under Hansen’s interpretation, such a warrant might be justified. The implications, he said, were troubling.

The court issued its decision in October 2023. Four of the seven justices upheld the warrant’s legality. They cited the narrow parameters of the search and the fact that it had been carried out by a machine, not a person. But they also acknowledged that the warrant lacked individualized probable cause—Seymour had not been a suspect before police accessed the data. For that reason, they found the warrant “constitutionally defective,” though they did not throw out the evidence obtained.

The ruling left the door partially open. Some law enforcement agencies expressed caution. The Denver office of the Bureau of Alcohol, Tobacco, Firearms and Explosives stated that it would consider using such warrants only in exceptional cases, and only with tightly limited search terms and timeframes. But not all departments took the same view.

Baker and Sandoval, the lead detectives on the Diol case, soon began fielding calls from officers in other jurisdictions seeking copies of their warrant. Baker reportedly considered using a similar tactic in a new investigation. Meanwhile, private consultants who had once specialized in helping police with tower dump warrants were now advising departments on how to craft keyword warrant requests to Google.

There is no public database tracking the use of reverse keyword warrants. But Andrew Crocker, an attorney with the Electronic Frontier Foundation, estimated that hundreds may have been issued. Crocker has described the tool as inherently dangerous. In his view, it could be used to identify political dissidents, undocumented immigrants, or individuals seeking reproductive care.

In a separate case now pending before the Pennsylvania Supreme Court, a keyword warrant was used to identify a suspect in a series of rapes. If upheld there, use of the warrants could accelerate.

Back in Colorado, the criminal case moved toward resolution. By mid-2024, all three defendants had entered plea agreements. Dillon Siebert was sentenced to ten years in juvenile detention. Gavin Seymour received forty years in adult prison. Kevin Bui, identified as the instigator, received sixty. While in custody awaiting trial, Bui had been found with fentanyl and methamphetamine concealed in his sock.

At sentencing, Amadou Beye—husband of Hassan Diol and father of seven-month-old Hawa—addressed Bui directly. Beye had been in Senegal awaiting a visa when his wife and daughter were killed. He never met his child. “I will never forget or forgive you for what you did to me,” he told the court. “You took me away from my wife… You took me away from my baby that I will never have a chance to see.”

Bui showed little visible reaction. He wore a green prison jumpsuit, white sneakers, and clear-framed glasses. He read from a sheet of yellow paper, acknowledging blame. “I was an ignorant knucklehead blinded by rage. I’m a failure who threw his life away. I have no excuses and nobody to blame but myself.”

Three months later, in a recorded interview to Wired, Bui’s tone was more casual. He described his daily routine: attending classes, working out, watching television with other inmates. He followed the Denver Broncos and Baltimore Ravens, and said he had recently started watching Sex and the City.

He did not comment on the loss of internet access or the limits of life behind bars. For someone born in the digital age, the absence of connectivity might have been significant. But Bui expressed no frustration. “I’m in a good place now,” he said.

The call ended shortly afterward. He had an appointment at the prison barbershop.