NAPA (CBS SF) — Napa police arrested five men in possession of nearly 600 pounds of marijuana as well as cash and guns at a residence in Santa Rosa on Wednesday following a long-term police investigation.

The Napa Special Investigations Bureau (NSIB) arrested Javier Caballero Perez, 42, Crisanto Guevara, 23, and Victor Farias, 27, all transients from Mexico, and Marvin Garcia, 22, an Oakland resident, on suspicion of possession of marijuana for sale.

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Additionally, Abel Caballero Perez, 36, a transient from Mexico, was arrested for being armed while committing a felony, in addition to the marijuana offense, police said.

In August 2013, the NSIB launched an investigation into a large-scale marijuana grow operation in the Walter Peaks area of Pope Valley, part of the Land Trust of Napa County, police said.

On Aug. 7, the NSIB and the California Department of Justice’s Campaign Against Marijuana Planting program eradicated hundreds of marijuana plants in the area.

During the eradication, detectives found that trees and shrubs on the hillside had been cut, fertilizer introduced to the environment, and that a spring had been dammed up.

According to the detectives, water from the spring had been diverted to irrigate the marijuana plants.

A campsite filled with garbage was located in the area adjacent to the spring. Detectives recovered a piece of evidence at the campsite that led them to serve several search warrants in an effort to identify members of the organization and those responsible for the grow operation, police said.

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On Wednesday, Napa detectives went to a residence located in the 1000 block of Leddy Avenue in Santa Rosa in an effort to identify not only the marijuana growers, but the entire criminal support structure of the organization, police said.

Upon arrival at the home, detectives smelled a strong odor of cultivated marijuana. They made contact with individuals outside the residence and obtained a search warrant.

About 585 pounds of processed marijuana, two handguns, and more than $7,000 in suspected drug proceeds were seized from the residence, according to police.

Detectives arrested the five suspects at the residence and booked them into Sonoma County Jail.

According to police, the five suspects are also being held on U.S. Immigration and Customs Enforcement detainers.

Detectives said additional arrests are expected to follow.

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