BAKERSFIELD, Calif. (KGET) — A federal grand jury has indicted 12 Central Valley residents arrested earlier this month in the culmination of an 18-month-investigation called “Operation Dark Nodes.”

More than 15,000 suspected fentanyl pills, 990 grams of fentanyl, 10 pounds of methamphetamine, 7 pounds of heroin, 112 pounds of marijuana, 13 guns and $60,000 in cash were seized during the operation, authorities said.

On Thursday, a grand jury returned an 11-count indictment against Bakersfield residents William Arthur Poush, 43, Rosa Fernandez, 43. and Dale Vincent Perez, 39, as well as North Hollywood resident Timothy Robert Hingston, 39, and Montrose resident Spencer Matthew Hopper, 35, according to a release from the U.S. Attorney’s Office, Eastern District of California.

Poush and Fernandez sold more than 50 grams of meth to a confidential informant on Jan. 20 and Feb. 24, according to the release, and Poush also sold more than 50 grams of meth and fentanyl pills to a confidential informant on May 11.

Federal documents say a confidential informant reported Fernandez, who goes by “Madrina,” is affiliated with the Mexican Mafia and distributes drugs in the Bakersfield area. The informant said Fernandez is also affiliated with the East Side Bakers street gang.

Poush is a suspected member of the East Side Bakers who was in business with Fernandez, according to court filings.

On Aug. 13, Hingston and Hopper gave more than 500 grams of meth and 400 grams of fentanyl to Poush, who planned to distribute the drugs, the release said. Days later, Poush and Perez conspired to possess with intent to distribute more than 50 grams of meth, and on Sept. 1 Poush possessed more than 50 grams of meth with intent to distribute, according to the release.

A three-count indictment was returned against Dale Wesley Hubbard, 49, and Darlene Crystal Viera, 40, of Bakersfield, charging them with conspiracy and distribution of meth and fentanyl, according to the release. It’s alleged they sold drugs to confidential informants on May 3 and May 25.

A three-count indictment was also returned against Bakersfield residents Manuel Yanes, 25, and Jorge Luis Yanes, 28, charged them with conspiracy to distribute and distribution of meth, authorities said.

Luis Mauricio Castenon, 33, and Bryan Steven Reyes, 28, of Bakersfield, were charged in a four-count indictment with conspiracy to distribute and distribution of meth, according to the release, and a two-count indictment against Bakersfield resident David Garcia, 35, charged him with being a felon in possession of a firearm and possession with intent to distribute meth. A search of Garcia’s vehicle during a traffic stop turned up a loaded gun and more than 50 grams of meth, authorities said.

The defendants face various maximum sentences if convicted, with some facing a 10-year prison term and others a life sentence.