Five down in Apt. 307: Mass fentanyl deaths test a Colorado prosecutor
COMMERCE CITY, Colo. — From the doorway of Apt. 307, District Attorney Brian Mason could see the five bodies inside. They lay awkwardly on the floor and couch, their arms and legs contorted — a sign of sudden collapse.
A man in jeans and closest to the door was splayed on his back, his left leg bent at an odd angle. Not far from him, a woman with long brown hair was slumped on the kitchen floor, her face pressed against a lower cupboard. Another woman, in a black sweatshirt, lay just past the kitchen counter nearby. On a love seat toward the back of the room, a man sat frozen. A woman in a gray T-shirt had toppled over him, her head resting on his chest. Blood dripped from their faces.
A mass murder, Mason thought.
Mason, a slim 45-year-old who grew up in Colorado, had arrived at the suburban Denver apartment complex shortly after 8 p.m. on Feb. 20. It was such a frigid night that his knees were shaking. He climbed the outside staircase to the third floor with Sgt. J.P. Matzke, the supervisor of a local drug task force.
The scene looked like a party gone terribly wrong, Matzke told Mason. Five people down. Crime-scene technicians collecting evidence inside were suited up in Hazmat gear. They were worried that whatever substance had caused so many people to die simultaneously might still be in the air. They had tested for carbon monoxide and ruled that out.
A partly empty Crown Royal whisky bottle stood on the kitchen counter among plastic cups, empty shot glasses and cut orange straws. In the middle was a mirrored tray with lines of white powder. A red heart-shaped balloon floated above, tied by a string to a bouquet, remnants of Valentine’s Day the week before. In the center of the room was an empty baby swing.
The first police officer on the scene, a mother herself, had found a crying 4-month-old baby girl in a pink bassinet in another room. She had been alone for nearly 12 hours. She was one of seven children who lost a parent that night.
Not everyone at the party had died, Matzke told Mason. The police officer had found a disoriented woman inside. At first, the woman tried to shield the white powder and told the officer she and her friends had all just fallen asleep.
“We took cocaine, and that’s it,” she mumbled before she was taken to a hospital.
But that wasn’t correct.
A gloved investigator sealed the white powder into plastic bags and scanned them with a handheld laser tool called TruNarc. Mason watched, fascinated. He had never heard of TruNarc, let alone seen it in action. The $30,000 device compared the substance with nearly 500 possible drugs.
The small orange screen flashed the word “Fentanyl.”
Exactly what Mason had feared. He had been warning people for months about deadly fentanyl mixed into recreational drugs.
The powerful, intensely addictive opioid has unleashed the most lethal narcotics crisis in U.S. history. Deaths caused by the drug are officially recorded as overdoses, but to Mason, that did not capture what really happened in Apt. 307.
It was a poisoning, he thought.
More than 107,000 people died in the United States last year by overdosing on illegal drugs. That is the country’s highest figure ever, and two-thirds of the deaths were attributed to fentanyl. Fentanyl deaths have nearly doubled since 2019.
Fentanyl death rates
in U.S. counties
Deaths per 100,000 people
Fentanyl death rates in U.S. counties
Deaths per 100,000 people
Fentanyl death rates in U.S. counties
Deaths per 100,000 people
Fentanyl death rates in U.S. counties
Deaths per 100,000 people
Some of the dead had sought out the drug and used too much of it, but many others, like the five in Commerce City, had no idea that they were taking something that would kill them with the speed of cyanide.
Fentanyl is up to 50 times more powerful than heroin, putting users on a razor’s edge between intense pleasure — the high — and mortal peril. Under proper medical supervision, it is extremely effective for treating severe pain because of its ability to depress the central nervous system. But when too much fentanyl hits the bloodstream, it can quickly trigger respiratory failure and cardiac arrest.
The Denver area was becoming a transportation hub for the synthetic opioid. Mason had been briefed by the police and the federal Drug Enforcement Administration that Mexican cartels were sending massive amounts of fentanyl, either mixed into counterfeit pain pills or in powdered form, across the southwestern U.S. border.
From there, drug dealers moved the fentanyl through Arizona, California, New Mexico and Texas and into Colorado, where two large interstate highways converge. The loads were then smuggled to Chicago and out across the country. Police were finding fentanyl in cocaine, heroin and methamphetamine.
Last December, Mason gave a speech with the Colorado attorney general warning about the terrifying new threat. “Fentanyl is killing our kids,” Mason said.
Then, on the Sunday of Presidents’ Day weekend, the nation’s largest-known mass fentanyl poisoning hit his own district.
Mason left the apartment and walked back downstairs to a huddle of police officials. The parking lot of the North Range Crossings apartment complex was closed off with yellow tape and awash with flashing red lights and dozens of police officers, firefighters and crime scene technicians. Officers were trying to hold back neighbors and distraught family members crying and demanding to know what had happened.
Mason looked over at the reporters behind the yellow tape. He walked toward the glow of the lights readied for the 10 p.m. live newscast.
As a prosecutor for 15 years, Mason had made it a rule not to talk to the news media this early in an investigation. But tonight was different.
Mason, a father of three, was terrified. How much more of this bad batch of drugs was out there? he wondered. How many more people were going to die tonight?
“No drug is safe right now,” he told the reporters. “People who are taking drugs and not knowing that fentanyl is laced within them are dying. And tonight, tragically, it appears that five of our fellow citizens died because of it.”
As he turned away from the cameras, his mind pivoted back to the apartment. Who had sold them the drugs? If investigators found the dealer, could they prove that the person had intentionally added fentanyl? Did the dealer even know it was in the cocaine?
So much felt unknown to Mason that night. But he was sure of one thing: These deaths were not a blameless accident. They were a crime.
‘We’ll find them’
At a meeting of local and federal investigators a week later, Mason learned more about the five people who died in Apt. 307. On a screen, police shared a detailed timeline and what they knew about the victims.
The five were good friends who had gathered for a small party late at night. The hosts were Sabas “Sam” Daniel Marquez and Karina Joy Rodriguez, both in their 20s, who lived with their 4-month-old baby, Aria. Sam and Karina had gone to dinner with his sister, Cora Marquez, 29, and her husband, Humberto Arroyo Ledezma, 32, and invited them over afterward. Two friends from Karina’s waitressing job at Mickey’s Top Sirloin steakhouse, Jennifer Danielle Cunningham, 32, and Stephine Monroe, 29, joined them in the apartment.
The five people who died in an apartment in Commerce City, Colo., on Feb. 20 are: above left, Sabas “Sam” Daniel Marquez, Karina Joy Rodriguez, while she was pregnant with her daughter, Aria, and Stephine Monroe; top right, Humberto Arroyo Ledezma; above right, Jennifer Danielle Cunningham. (Photos provided by Derron Reed, Irma Ledezma and Debbie Kerr.)
From everything the detectives could piece together in the first days, no one at the party had meant to buy fentanyl. Whoever brought what they thought was just cocaine into the apartment had meant to share it for an evening of fun with friends. There was so much fentanyl in the white powder that the drug-testing device did not initially detect cocaine. By snorting the drug commonly sold in counterfeit pill form, the group ingested the fentanyl in one of the most dangerous ways because it hit the bloodstream faster.
The drug has challenged police and emergency responders as no other illegal narcotic has. A higher-potency batch can rapidly trigger a wave of overdoses, sending authorities racing to administer the opioid antidote naloxone, which can bring victims back from the brink of death. But fentanyl often kills before paramedics can arrive, especially in the case of users with no built-up tolerance for opioids.
Mason and the investigators knew that on Jan. 28, in another fentanyl poisoning, authorities had linked a string of deaths in D.C. to a bad batch of cocaine. The District’s police chief would later call the overdoses “probably the worst I’ve heard of.” In St. Louis, paramedics had returned again and again over a February weekend to an apartment complex where 11 people overdosed and eight died. All had smoked crack cocaine laced with fentanyl.
There would be more fentanyl mass poisonings in the next two months — at least seven separate instances resulting in 58 overdoses and 29 deaths. The drug is disproportionately killing Black people and Native Americans. In Cortez, Colo., three Native Americans died in a motel room. During spring break in South Florida, six young men, including five cadets from the U.S. Military Academy at West Point, overdosed but survived. Over an April weekend, 17 Black people in two D.C. neighborhoods overdosed, and 10 of them died.
The sheriff in Gadsden County, Fla., said that fentanyl “was not in my vocabulary” until police linked fentanyl-laced cocaine to at least six deaths and 10 nonfatal overdoses over a couple of days in July. “It hit us like a ton of bricks,” said Sheriff Morris Young.
Many of these people had used what they thought was cocaine or crack, authorities said. A Washington Post analysis of data from the Centers for Disease Control and Prevention found that in 2021, fentanyl was involved in 74 percent of heroin deaths, 71 percent of cocaine deaths and 54 percent of meth deaths. In fact, yearly cocaine fatalities over the past decade have quintupled, and 90 percent of that rise can be explained by fentanyl.
Mass overdoses in 2022
Law enforcement officials think many more mass poisonings have not been counted. But the U.S. government does not track mass-overdose events — not the DEA, the CDC or the White House Office of National Drug Control Policy.
As Mason listened to the investigators, he wondered why someone had put fentanyl in the cocaine used at the party.
Mason was often asked that question. In his many meetings with drug agents, he learned that dealers have been taking advantage of fentanyl powder’s cheap abundance and supreme potency to “spike” their cocaine, heroin and meth. The drug allows them to deliver a more powerful high and keep addicted clients coming back for more.
Counterfeit pills that have caused deaths are sometimes called “kill pills” or “hot pills.” Customers who can tolerate opioids often seek out the dealers who can deliver the more powerful high.
But in some cases, street dealers do not even know that fentanyl is in the cocaine they are selling. And the recipe is not consistent; like the distribution of chocolate chips in cookies, some of the mixed drugs have more fentanyl than others.
At the end of the hour-long presentation, Mason looked around at all the police brass. He was hopeful. The federal officials had said they would contribute any forensic resources investigators needed. Police detectives already had several promising leads.
“We’ll find them,” David Olesky, the then-acting assistant special agent in charge of the DEA’s Denver division, confidently told a local TV reporter.
This was the first big test of leadership for Mason, who just the year before at 44 had become the elected district attorney — the chief law enforcement official for Colorado’s 17th Judicial District. He had political ambitions. Mason, the son of an Air Force captain, had decorated his childhood bedroom not with sports stars but with posters of former U.S. presidents. After college, he got a job as a legislative aide in the Clinton White House and worked as a staffer for a Democratic congressman. His district attorney’s office displays photos of him with four presidents, along with models of Air Force One and Marine One.
Mason’s twin brother, Jeff, had become a prominent White House reporter in Washington. And from his own time in the nation’s capital, Mason knew how important it was for federal agencies to focus their attention and resources on a local case like this. He felt pressure to find those responsible for the five deaths and provide justice for the victim’s families.
Success in the Commerce City fentanyl case could raise awareness of the drug’s alarming dangers — and put Mason in the center of the national campaign.
Over the next weeks and months, Mason worked closely with the investigators, who traced the movements of everyone in that apartment in the two days before they died.
Mason learned that a camera on a neighbor’s doorbell had recorded when each person walked into Apt. 307 between 1 and 2 a.m. on Feb. 20. Investigators didn’t know precisely when they died. But they knew that they all fell to the ground suddenly — so quickly that no one had a chance to reach for their nearby cellphones.
About 12 hours later, Celina Fisher arrived at the apartment to check on her brother, Sam Marquez, because he wasn’t answering his phone. No one answered the door, which was unlocked.
She stepped inside and screamed. Her brother was lifeless on the floor near the door.
Jennifer and Stephine lay on the floor on either side of the kitchen counter. On the surface were alcohol and lines of white powder.
On the couch, Sam’s partner, Karina, slumped on top of her brother-in-law, Humberto.
Celina’s stepsister, Cora, was alive but dazed. She stirred. “We’re okay,” she told Celina as she was coming out of a stupor. “We’re okay.”
At first, Celina didn’t notice her brother’s 4-month-old baby in her bassinet. She was behind a closed door to the master bedroom.
Celina ran to her brother, yelling his name, trying to wake him. She pulled out a canister of the naloxone spray Narcan. She carried the overdose antidote because she had used opioids before and was aware of the dangers. She pushed the white tube up his bloodied nose, squeezing the medicine. But he was already cold to the touch. She left him and went around the room, shouting at the others, trying to wake them. No one moved. Celina called 911 at 3:37 p.m.
“There’s one, two, three, four, five people!” Celina shouted into the phone.
When the police arrived, Cora told them her husband, Humberto, was diabetic and needed medicine, not realizing he was dead. They ushered Cora and her baby niece into ambulances. Crime scene technicians spent the next 12 hours collecting evidence at the apartment. Detectives executed 10 search warrants for the phones, cars and homes of each person in Apt. 307.
They searched the GPS history on the victims’ phones to determine where they had been. They pulled together hundreds of hours of videos from surveillance cameras that covered the victims’ workplaces, homes, a bar where two of them had gone beforehand and the apartment where the five died. They read their texts and examined their call records. They scrutinized every detail in their lives — including the money and keys in their pockets and purses and the people in their social media networks.
One of the phones could not be cracked. It belonged to Jennifer, a manager at Mickey’s. Friends and relatives told police they didn’t know the password.
Investigators tested the baggies of white powder and examined the packaging for fingerprints and DNA. They analyzed the quantity and toxicity of the drugs found in the apartment.
Fentanyl’s deadly surge
Nationwide, the DEA has found that the potency of pills with fentanyl has increased in samples taken over the years, from 1.3 milligrams per pill in 2017 to 2.34 so far this year — just above the lethal dose. It is a sign the nation’s opioid tolerance is going up. The cartels are boosting the potency of their fentanyl pills because habituated opioid users want the higher doses. Those who do not frequently use opioids or have never taken them are most at risk of being killed by the stronger drugs.
Autopsies conducted on the five found marijuana, alcohol, cocaine and fentanyl in their blood. The amount of the synthetic opioid in their systems was far more than a lethal dose. Fentanyl reduces blood pressure and slows breathing, and fluid fills the lungs. Lack of oxygen turns fingertips and lips blue or purple and damages the brain. As the heart rate drops, blood seeps from the nose and mouth along with a white foam.
The investigators set up an anonymous tip line to identify suspects. They offered a reward for any information about fentanyl distribution in the area.
Two months in, Mason studied the scattering of evidence that police had gathered. There were the drugs: Police had the white powder found on the kitchen counter. They also found three baggies of cocaine in the apartment — two on the kitchen counter and one in a purse. Two bags were laced with fentanyl, one was not, Commerce City Police said. One was older and had accidentally been washed in the laundry, making it even more difficult to determine who could have sold it.
Detectives had narrowed their focus to three “people of interest” in the area who could have been the source of the drugs. But which of those three was connected to a bag that contained fentanyl?
Text messages showed that Jennifer, Stephine and Karina had met up earlier at Jennifer’s house and shared cocaine. The group then separated: Jennifer and Stephine went to a bar together, and Karina returned to Apt. 307, where she and her partner, Sam, would host the others. About midnight, Karina sent a text to the women at the bar asking if they could get more cocaine. If not, she said, they should come over for a drink anyhow. Stephine replied, saying that Jennifer had a bag she found in her laundry. They told Karina they were trying to get some more and mentioned the names of two people they could ask. But no text message indicated that they managed to find cocaine from a specific source.
Detectives weren’t getting the break they needed. Two potential suspects denied responsibility; the third had died in the apartment. One man police questioned said that he did sell cocaine to someone connected to the party the night before, but that his powder did not have fentanyl in it because he and his brother had sampled it and would have died.
Cora, the sole survivor, cooperated with police but did not provide any information that could help them trace the source of the fentanyl.
Mason’s case was becoming a messy, forensic jigsaw puzzle.
Prosecuting fentanyl dealers
Even if investigators could make the connection, Colorado did not have a charge for “distribution of fentanyl causing death.” First-degree homicide was off the table because the charge required that the dealer intended to kill the customers — and there was no evidence of that so far. Without being able to tie anyone to the drugs in the apartment, Mason wasn’t even going to be able to bring a misdemeanor charge.
This was a huge case, with shattered family members pleading with Mason to do something. Legislators already had been looking at stronger laws, and the horror of the Commerce City deaths created new momentum.
Even as the details of Mason’s prosecution case remained cloudy, the political urgency was clear.
For Mason, the case was a platform to advocate for harsher penalties for future fentanyl crimes.
In mid-April, he sat before a packed hearing room inside the gold-domed Colorado Capitol in Denver to argue his case for legislation that would make distribution of fentanyl causing death a crime in Colorado. At least 23 states and Congress have passed similar legislation, increasing penalties for dealers whose drugs kill users.
He felt the tension in the room. Several legislators and activists were fighting the bill because they thought it furthered the failed war on drugs, targeting people of color and sending people struggling with addiction to prison rather than providing them treatment.
“As most of you surely know, just a few months ago, we lost five people in one single incident of fentanyl poisoning in Commerce City. And at the time, it was the single largest number of deaths from fentanyl poisoning in the country,” Mason said. “I knew then and predicted then that we would not keep that record for long, and we haven’t. But it is a challenging example and a powerful example of how much fentanyl is ravaging this state.”
Later in the hearing, Karina’s sisters, Feliz Sánchez García and Mileiah Rodriguez, testified.
Karina’s sisters and her mother, Debby Garcia, were still mourning Karina’s death — and caring for her baby girl, Aria, who had been left alone for 12 hours in Apt. 307. They were struggling to comfort Karina’s 10-year-old son, Josiah, who lived with his father.
Feliz vividly remembered the cold night she waited at the edge of the police perimeter for news about her sister. She had spotted an officer who seemed to be in charge. People were shouting at him, trying to find out what happened.
Maybe if I just ask nicely, he’ll say my sister is alive, she thought.
Now a photo of Karina’s smiling face was pinned to her sweater as she sat beside her sister Mileiah in the statehouse hearing room.
The sisters said they hoped their prepared remarks, read from their cellphones, would finally correct the false impression in news reports that their sister was an irresponsible mother addicted to drugs. They feared what their niece and nephew might read online about their mother when they grew up.
“Four month-old girl orphaned after her mom and dad took her to drug-fueled house party in Colorado where they died after taking ‘fentanyl-laced cocaine,’ ” one headline had read.
They testified that their sister was not a regular drug user. She had been devoted to the baby girl she had always wanted, Feliz said. She didn’t use drugs while she was pregnant, nor while she was breastfeeding. Karina spent most nights at home, because she didn’t want to leave her baby with anyone else.
“She didn’t have a drug problem, but she decided to have a little fun one night,” Mileiah, the other sister, testified through tears. “And she was poisoned. Even if she did decide to use cocaine that night, she didn’t deserve to die. She was murdered.”
“She was not a person who struggled with addiction,” added Feliz, who was sitting beside her sister. “She said in the weeks before her death that she was the happiest she had ever been.”
Mason listened to the sisters with rapt attention. Up to this point, he had avoided interacting with any of the victims’ relatives because he knew that investigators were interviewing family members to determine whether any of them might be linked to the drugs.
As Mason watched the sisters testify, he decided he wanted to meet them.
Mason approached them in the hallway outside the hearing. He hugged them.
“I am so sorry for your loss,” he said as they wept.
The hearing lasted 12 hours, and legislators passed the bill in May.
Mason joined Colorado Gov. Jared Polis (D) on the steps of the Capitol as Polis signed the fentanyl law. Karina’s family and other victims’ relatives stood behind him, holding up photos of loved ones who had been killed by fentanyl.
Feliz and another family member read off the names of 23 people killed by fentanyl whose families had attended the hearing.
“They all had names, and they’ll never be forgotten,” she said.
Mason embraced Feliz. Her testimony had been critical to the bill’s passage. But the district attorney could not use the newly created charge retroactively in her sister’s case.
“No one should die from fentanyl poisoning,” Mason said from the lectern. “This bill is a start.”
As she left the Capitol that day, Feliz wondered when Mason would hold a big news conference to announce that he was charging a drug dealer with murder for the deaths of her sister and the four others.
Two months later, on July 27, Mason gathered the federal and local investigators in his office’s law library. He went around the table and asked each of them what evidence had been gathered and whether there were any developments.
When they finished, he had one final question: “So what you all are telling me is that we don’t have the evidence right now to charge this crime?”
They all said yes.
On Sept. 14, Mason gave the news conference he had long dreaded. Flanked by the deputy U.S. attorney in Colorado, J. Chris Larson, and Commerce City Police Commander Dennis Flynn, Mason looked glum.
“Five residents of our community died from fentanyl poisoning in what was one of the largest mass incidents of this nature in the United States,” he began. “Since that time, we have had a multiagency, massive investigation into their deaths.”
“As of this moment today, we do not have the evidence to charge anyone with these deaths,” he said.
For now, the Commerce City case was cold.
“I genuinely hope that someday we will be able to find and hold accountable those who are responsible,” he said. “But, based on the evidence that we have today, we do not have the ability to charge anyone today. And I do not know that we ever will.”
Karina’s sister Mileiah was watching Mason’s news conference on Facebook at the doctor’s office where she worked. Mason had already alerted her family, but she still couldn’t believe what he was saying.
“As a family member, we’re extremely disappointed,” she immediately wrote on Facebook.
Derron Reed, the partner of Stephine, could not even watch Mason’s news conference. He had been frustrated and angry over the pace of the investigation all along. And now, after six months, the police had no answers. How was he ever going to explain to their two children, 10-year-old Ezra and 4-year-old Kendall, that their mother had been killed and that no one was going to be punished?
Amid the grief of losing his partner of 15 years, Derron had been struggling to help his children make sense of their mother’s death. He told his son that adults sometimes did things to relieve stress that children should not do.
“She was just having fun. She didn’t take her own life,” he said. “She was poisoned.”
The investigation had faded, but the impact on Commerce City was lasting. Denver authorities reported a sharp increase in requests for the opioid reversal drug naloxone. The grisly image of five dead men and women flashed back into the mind of the first police officer on the scene every time she drove by the apartment complex. A police trainee was so traumatized by what he had seen that he quit the force. The former Commerce City police chief said that in his nearly 31 years in law enforcement he had never seen anything so horrific.
Celina Fisher, who had found her brother and the others dead in Apt. 307, struggled with the trauma. Her substance abuse worsened, according to a relative.
On Halloween night, Celina was found unconscious in a park. She was rushed to a hospital and died the next day. The medical examiner listed alcohol and methamphetamine toxicity as the cause of death.
Mason returned to the North Range Crossings apartments one more time. He parked his car and walked to the building where the five had died. He hadn’t been back there since that night in February when he saw what he was sure was a mass murder.
The vibrantly colored apartment complex looked and felt completely different to him in the daylight. Mason thought about how everyone had wanted answers that night — and had worked so hard subsequently to get them. It didn’t matter. He couldn’t make a case, and it haunted him.
He walked back to his car. The fentanyl crisis in the Denver area and across the country was growing worse.
Later that week, Mason would announce that he was charging two suspected drug traffickers with the death of their 1-year-old. She had ingested 10 times the amount of fentanyl that would kill an adult.
How are we ever going to be able to stop this? Mason wondered.
If you or someone you know needs help with mental health or substance use issues, you can call the government’s National Helpline at 1 800 662-HELP(4357). You can also reach the National Suicide Prevention Lifeline at 988, or a crisis counselor by messaging the Crisis Text Line at 741741.
About this story
Overview: From Mexican labs to U.S. streets, a lethal pipeline