They found several suitcases loaded with brick-shaped bundles of what appeared to be heroin. But lab tests determined that most of it — 141 pounds — was pure fentanyl, a synthetic and supremely dangerous opioid 50 times more powerful than heroin.
It was the largest fentanyl seizure in U.S. history. There was enough inside the apartment to kill 32 million people, according to the Drug Enforcement Administration.
The married couple who were arrested, Rogelio Alvarado-Robles, 55, and Blanca Flores-
Solis, 52, had no criminal record in the United States. They had flown to New York a few weeks earlier with Mexican passports. They had no weapons.
But they were drug cartel emissaries, investigators said, sent to broker the sale of tens of millions of dollars' worth of narcotics, like pharmaceutical executives on a business trip.
DEA agents say recent arrests reflect an emerging pattern, as Mexican trafficking groups attempt to turn New York City into their Northeast distribution hub. They operate with quasi-corporate sophistication and an inconspicuous, transient presence, sending sales teams to deliver staggering quantities of drugs and then quietly disappear.
This year, narcotics agents have seized more than 350 pounds of pure fentanyl in New York City, 10 times as much as they did in 2016. A calculated business decision appears to be behind the boom.
"The cartels realize that fentanyl is much more profitable than heroin," said James Hunt, head of the DEA's New York Division.
Unlike heroin, whose raw opium base must be collected from poppy growers in remote mountain valleys, fentanyl can be made in clandestine labs using relatively inexpensive chemicals. And because it is so much more potent, it can be diluted with cutting agents to make exponentially more street-level doses, whether in powder form or ersatz pills pressed to resemble brands such as OxyContin and Percocet.
"These guys are evil businessmen, but they are still businessmen," Hunt said. "I don't know of any other product where you could invest $3,000 and make millions."
More than 60,000 people died from overdoses in the United States last year, according to estimates from the Centers for Disease Control and Prevention, and deaths from synthetic opioids such as fentanyl increased fivefold.
According to DEA intelligence gleaned from wiretaps, about 80 percent of the fentanyl seized in the New York area appears to be linked to Mexico's Sinaloa cartel. The organization remains North America's dominant trafficking group, even as its leader, Joaquin "El Chapo" Guzman, awaits trial in a maximum-security jail in Lower Manhattan.
Sinaloa's smuggling machine has carried on without Guzman, meaning his legal defense may be funded in part with profits from fentanyl sales made just a few miles from his cell.
The Sinaloa group does not bother with retail-level commerce, according to the DEA. It uses New York to deliver large wholesale shipments to middlemen, typically local Dominican traffickers. Those groups distribute to markets in New England, Pennsylvania, Baltimore and other places where the opioid crisis is raging.
Late last month, as President Trump declared opioid addiction a public health emergency, Attorney General Jeff Sessions traveled to a mail inspection facility at New York's John F. Kennedy International Airport to praise the customs agents who have intercepted fentanyl shipments arriving from China.
"With synthetic drugs flooding our streets, drugs are now more powerful, more addictive and more dangerous than ever," Sessions said.
"Fentanyl is the number one killer drug in America," he said. "And as deadly as it is, you can go online and order it through the mail."
But Mexican traffickers are sending fentanyl through the U.S. interstate highway system, not the postal service, and in quantities that dwarf the amounts arriving in envelopes.
They smuggle it across the border in fake vehicle panels or commercial loads of produce, furniture, auto parts and other cargo, driving it across the country from California and Arizona.
The loads arrive at industrial parks in New Jersey, where cartel emissaries are sent to meet the shipments and oversee wholesale transactions. Then they must figure out what to do with bricks of cash that are even bulkier than the drugs.
The Bronx and northern Manhattan are choice locations for the traffickers, agents say, because their proximity to major bridges and highways offers the same logistical advantages sought by any commercial distributor.
Last month, narcotics agents arrested a Mexican driver in an industrial area of the Bronx with 37 pounds of fentanyl in the back of a delivery truck. The location was not far from a hotel where, in June, they seized 40 pounds of the drug stashed in a duffel bag.
Like the couple in Queens, traffickers appear to be avoiding high-crime neighborhoods where they might be at greater risk of being robbed or detected. DEA agents in August found 20 pounds of fentanyl and heroin at a $4,000-a-month apartment overlooking Central Park. The building's exterior had appeared in episodes of the sitcom "Seinfeld" as the apartment of the Elaine Benes character.
Inside, a Dominican drug gang was blending fentanyl and heroin in coffee grinders and stamping the drug packages with labels such as "Pray for Death," "Uber" and "Gilligan's Island." As police raided the apartment, an elderly resident came outside to walk her poodle. She complained to the DEA about her neighbors' loud music.
"Two years ago, any one of these seizures would have been huge," Bridget Brennan, New York City's special narcotics prosecutor, said in an interview. "But we've never seen volumes like what we're seeing now," she said. "Not even close."
The couple arrested in Queens face major drug trafficking charges. An attorney for Flores-Solis said she was not aware of any illegal activities that her husband, Alvarado-Robles, may have been involved in. His attorney declined to comment.
New York City's homicide rate soared in the 1980s, when Colombian traffickers dominated the cocaine trade, setting up extensive distribution networks and defending them with lethal force.
The Mexican traffickers flooding the city with fentanyl and other drugs are different. They largely eschew violence, and they don't carry guns. They are the sales teams — not the enforcement division — of Fentanyl Inc.
"They're smart," said Jimmy Arroyo, a DEA special agent who leads the team that in recent months has made several large busts linked to the Mexican traffickers. "They know that if they kill people, they will attract attention."
Last year, amid an unprecedented surge of opioids into New York City, the number of homicides decreased to 335, the lowest total since 1963.
This is not to say the cartels are not violent, only that they are strategic. In Mexico, where they kill easily and with near-total impunity, the homicide rate is at a 20-year high. And in some major New York drug cases, prosecutors say, their U.S. trafficking partners have been forced to send relatives to Mexico as insurance in case a deal goes bad. One major heroin dealer sent his own son.
Although the opioid boom hasn't led to more violence in New York, it has produced a staggering amount of death. The city had nearly 1,400 fatal overdoses last year, a 46 percent increase from 2015. Fentanyl showed up in 44 percent of autopsies.
Heroin spiked with fentanyl — known on the streets as "fire" — had been in the city's drug supply for years, but recent lab tests showed that doses were increasingly composed of cutting agents and pure fentanyl, which users say provides a more intense high than heroin alone.
It's also shorter in duration, requiring more frequent doses to avoid crippling withdrawal symptoms.
Prosecutors say there are signs that the Mexican trafficking groups have started taking steps to dilute their fentanyl shipments before delivery, apparently worried that the surge in overdose deaths could harm sales. Recent seizures have found pre-mixed packages with lower and somewhat less lethal concentrations of fentanyl.
"The cartels have their own self-interest at heart, and if they do nothing but put out fentanyl, they will kill their customer base," said Brennan, the special narcotics prosecutor. "From a business perspective, it's good to send a small, compact load, but if the person receiving it is not familiar with how to dilute it, you will kill too many people and draw more law enforcement attention."
Getting accurate test results on the composition of seized drugs now takes longer, because narcotics agents can no longer cut open packages to conduct field tests. The fentanyl is too dangerous; even a dusting of airborne powder can trigger an overdose. Narcotics agents must conduct raids using respirator masks, gloves and even full-body suits, and when they enter a "pill mill," they increasingly find criminals wearing the same gear.
DEA agents say they do not think that Mexican trafficking groups will eventually take over retail-level fentanyl distribution in New York. That would require far more personnel, exposing the organization to more arrests, and therefore more informants. They prefer to continue outsourcing and remain mostly anonymous in the drug trade.
The sales representatives who reach New York, communicating with encrypted software such as Silent Circle and Signal, are typically nameless figures whom narcotics agents have never seen. And in a matter of days or weeks, they're gone.
In June, when Arroyo's team seized 40 pounds of pure fentanyl at the Umbrella Hotel in the Bronx borough of New York, they arrested Carlos Ramirez, 25. He wore thick glasses, shorts and sneakers. He looked like he was in town for a comic book convention, not a massive fentanyl deal.
Prosecutors say he arrived from Lakeland, Colo. But a clerk at the hotel who remembered Ramirez said she spoke to him in Spanish. He had stayed there on other occasions before his arrest, she said, telling her he was a pipe fitter in New York for construction jobs. He asked her for advice on where to eat, and what clubs to go to. He told her he was from Sinaloa.
"It was strange," the clerk said. "I never saw him wearing any work clothing."