SNOHOMISH — Three men who were arrested in Snohomish earlier this year have admitted to peddling large amounts of heroin, likely as part of the Sinaloa cartel’s expansive reach into the U.S.

The men were caught in May with two kilograms, or nearly 4½ pounds, of Mexican brown heroin, worth hundreds of thousands of dollars on the streets, according to court documents. A Washington State Patrol detective assigned to Homeland Security Investigations wrote that the men are part of a drug trafficking ring that moves large quantities of heroin and methamphetamine from Sinaloa, Mexico.

The men earlier this month pleaded guilty to conspiracy to distribute controlled substances. They are scheduled to be sentenced in January in U.S. District Court in Seattle. They each face up to 20 years in prison.

Agents used confidential informants to buy heroin from Juan Carlos Andrade Bueno, 32, who was living in a Snohomish apartment, according to a probable cause affidavit.

Snohomish Police Chief John Flood told The Daily Herald in May that the building was relatively quiet, and hadn’t generated calls to 911. It wasn’t a place that officers noticed a stream of short-stay traffic, which often is a sign of drug deals.

Bueno first gave the informants heroin samples, and later introduced them to his meth source, detectives wrote. Police are seeing a resurgence of meth, likely also coming from labs in Mexico.

At a third meeting, Bueno arranged for an informant to take a pickup truck and instructed the buyer how to access a concealed compartment, which contained a kilogram of heroin. The informant later paid Bueno $34,000.

The two then arranged another sale for later in the week.

The informant met with Bueno at his apartment, planning to buy four kilograms of heroin. They had lunch and waited for the drop.

A Mercedes arrived later, and the driver and his passenger showed Bueno and the informant a box in the backseat. Detectives later obtained a warrant to search the car. They found about two kilograms of heroin inside the box, according to police reports.

Police arrested Bueno’s alleged suppliers, Ricardo Gerardo-Gallardo, 26, and Isaac Mariano Meza-Espinoza, 22. Both are not U.S. citizens, police reported.

Meza-Espinoza was involved in another Homeland Security investigation in 2014. He was just 20 when he was in a vehicle that an informant planned to meet to buy four kilograms of heroin. Police found a loaded .22-caliber handgun on the floorboard.

“Meza-Espinoza was supposed to follow up with investigators, but never did and investigators have not been able to locate him to date,” the detective wrote in court papers during the 2014 case.

Gallardo-Hernandez was pegged as the leader of the local drug organization. Bueno bragged to the informants that he also sells guns, according to court papers.

The three men were booked into the Snohomish County Jail for investigation of drug trafficking. The case was later transferred to federal court. A grand jury indicted the men in June.

Diana Hefley: 425-339-3463; hefley@heraldnet.com.