BOSTON — Three Southeastern Massachusetts men pleaded guilty today in federal court in Boston to their roles in a heroin and fentanyl trafficking organization that operated in Taunton and Boston, the U.S. Attorney's Office said.

David Tejeda, 35, of New Bedford, Jeffrey Freitas, 32, of Bridgewater and John Paul Tanguay, 34, of Taunton, each pleaded guilty to one count of conspiracy to distribute and possess with intent to distribute heroin and fentanyl, a news release from the U.S. Attorney said.

In February 2017, Tejeda, Freitas, and Tanguay were arrested and charged along with 20 other co-defendants. U.S. District Court Judge Indira Talwani scheduled the sentencings for Tejeda and Freitas for Jan. 4, 2018, and Jan. 5, 2018, respectively. U.S. District Court Judge Leo T. Sorokin scheduled Tanguay’s sentencing for Oct. 16, 2018. As part of the District Court’s RISE program, Tanguay will participate in supervised drug treatment in advance of his sentencing hearing, the news release said.

From mid-2016 through February 2017, federal law enforcement investigated two drug trafficking organizations operating in Taunton and Boston led by Jose Antonio Lugo-Guerrero, 32, a Dominican national operating in Boston, and Fernando Hernandez, 42, a Dominican national living in Providence, R.I. Hernandez allegedly ran a heroin and fentanyl trafficking organization in Taunton. The organization sold heroin and fentanyl to customers, including Tanguay, who re-distributed a portion of the drugs he obtained. It is alleged that Hernandez obtained drugs from a network of suppliers that included Lugo-Guerrero, authorities said.

Lugo-Guerrero allegedly operated a drug trafficking organization in Fall River and Boston and sold to numerous customers, including Tejeda and Freitas, the U.S. Attorney's office said, adding that it is further alleged that Lugo-Guerrero and his associates obtained a significant quantity of illegal drugs by robbing other drug traffickers.

Hernandez and Lugo-Guerrero each pleaded not guilty and are awaiting trial.

The conspiracy charge against Tanguay and Tejeda provides for a sentence of no greater than 20 years in prison, a minimum of three years and up to a lifetime of supervised release and a fine of $1 million. Freitas faces a sentence of at least five years and no greater than 40 years in prison, a minimum of four years and up to a lifetime term of supervised release and a fine of $2 million.

Acting United States Attorney William Weinreb; Michael Ferguson, Special Agent in Charge of the Drug Enforcement Administration, Boston Field Division; Colonel Richard D. McKeon, Superintendent of the Massachusetts State Police; Fall River Police Chief Daniel S. Racine; New Bedford Police Chief Joseph C. Cordeiro; Taunton Police Chief Edward James Walsh; Boston Police Commissioner William B. Evans; and Bristol Country District Attorney Thomas M. Quinn made the announcement today. Assistant U.S. Attorney Ted Heinrich of Weinreb’s Narcotics and Money Laundering Unit is prosecuting the case.