A command came from the officers in the front of the black-and-white: "Seat belts off—in case we start taking fire."

But there was no shootout. Just a tense half hour as a phalanx of two dozen state police—agents from the Department of Cannabis Control (DCC)—kept snipers trained on the house, waiting for the second of two suspects to emerge.

When she finally did, petite and barefoot in a black dress, the effect was mercifully anticlimactic.

Illegal cannabis cultivation operations, or "grows," are a multi-billion-dollar-a-year industry in California, dominated by a mix of transnational criminal organizations that authorities believe are symbiotic, if adversarial.

When agents serve a warrant, they often find human trafficking victims, automatic weapons, booby traps and, increasingly, banned toxic pesticides smuggled from China.

This particular raid, in Lancaster, netted around 1,020 plants—a modest haul compared with the herculean grows that have become common across California's booming black market.

But such mild suburban tableaus belie a sleeping, sinister threat.

"What we have right now is organized criminal enterprises literally destroying the city building by building as they modify them for illegal cultivation," Mike Katz, a Lancaster code enforcement officer who heads the city's cannabis unit, told The Epoch Times.

"They're endangering the families who will occupy those buildings in the future, they are lowering the value of neighboring properties and dragging the whole community down," he said.

'Super Toxic'

Buildings contaminated by illegal grows are dangerous because the harsh pesticides growers use permeate every surface—ceilings, walls, floors, vents and drywall.

Toxic black mold blooms in the 75 percent humidity needed to grow marijuana. The massive amounts of water and electricity required to sustain an operation can result in structural damage to vents and sunken floors, overloaded transformers and corroded wiring just itching for a fire.