SAN FRANCISCO (CBS SF) — The alleged kingpin and six of his associates have been charged with drug trafficking after federal agents shutdown a criminal organization responsible for a pipeline funneling illegal fentanyl to San Francisco Bay Area streets, according to the U.S. Attorney’s Office.

Acting United States Attorney Stephanie M. Hinds and Federal Bureau of Investigation Special Agent in Charge Craig D. Fair announced Tuesday that Javier Castro Banegas-Medina, a/k/a Gio, was the alleged leader of a group called Castro DTO.

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The criminal organization kept large amounts of fentanyl stashed in houses in Oakland and San Leandro. The deadly illegal drug was passed along in a distribution chain that flowed throughout the Bay Area, including San Francisco, Concord and Oakland.

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Castro, Elmer Rosales-Montes and Jose Ivan Cruz-Caceres were charged Tuesday with conspiracy to distribute more than 40 grams of fentanyl. If convicted, the defendants face a maximum prison term of 40 years, with a mandatory minimum of 5 years.

William Joseph Laughren has been charged with possession with intent to distribute fentanyl. If convicted, Laughren faces a maximum prison term of 20 years.

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Jihad Jad Tawasha, Keny Alduvi Romero-Lopez, and Heather Borges were charged with possession with intent to distribute more than 40 grams of fentanyl. If convicted, Tawasha, Romero-Lopez, and Borges each face a maximum prison term of 40 years, with a mandatory minimum of 5 years.

The complaints filed against the defendants describe how law enforcement investigators conducted a wiretap investigation to develop evidence regarding the distribution of fentanyl.

Law enforcement agents executed arrest warrants at the Castro DTO stash houses on May 25 where they found approximately 19 kilograms (nearly 43 pounds) of fentanyl — much of it hidden in fence posts surrounding one of the residences. The seizure was the largest federal seizure of fentanyl ever in the Northern District of California.

Federal agents also discovered dyes likely used to color the fentanyl prior to sale and approximately $36,000 in cash.

The complaints and documents filed in the cases describe numerous transactions that occurred in the Spring of 2021.

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According to the complaints, it is estimated the DTO has filled over 100 orders for suspected fentanyl between approximately April 21, 2021 and May 19, 2021.