An investigation by the Drug Enforcement Agency into the heroin trade in the Bay Area led to the arrest of a Turlock man that officials suspect was a major supplier for the region.

Federal prosecutors have charged Arturo Castro Zavaleta of Turlock with two felony drug offenses after DEA agents found a trove of narcotics at his Turlock home.

Zavaleta first came to the attention of DEA agents as they were investigating various suspected heroin dealers in the Vallejo area. The San Jose Mercury News, citing the criminal complaint, reported that an undercover DEA agent was able to obtain a search warrant to track the GPS signal on Zavaleta’s cell phone, which led to his residence in the 300 block of Clark Street in Turlock.

Agents conducted a raid on Zavaleta’s home on June 3 and found drugs and guns. Agents seized 300 opium poppy bulbs, 200 marijuana plants, 10 pounds of heroin, one pound of fentanyl, and three guns hidden under a mattress.

Zavaleta allegedly admitted the marijuana and heroin were his, according to the Mercury News. He also said he was not in the country legally.

Zavaleta was charged with possession with intent to distribute heroin and manufacturing of at least 100 marijuana plants.

The arrest is part of a larger investigation into the Aryan Brotherhood prison gang on allegations of racketeering and violent crimes that has already resulted in the arrests of 25 individuals.