“I gave up being objective about this a long time ago,” Thompson says. “I think it was the day I looked at a map and saw a grow site maybe 100 yards upstream of a place I’ve taken my kids to play in the water and fish. That makes it a personal issue.”

It’s an unusual position to be in for a scientist trained in dispassionate data collection and objectivity above all, and one that’s often uncomfortable as well as dangerous. Gabriel’s many published papers and presentations on the topic of pot poisons have raised his public profile significantly. In the heart of drug country, that’s not a good kind of notoriety.

Growing marijuana has been a way of life in northern California for decades. Even though more and more is being grown legally, Gabriel’s inadvertent role as “the scientist who helps cops raid pot farms” has—in some eyes—brought unwelcome attention. In Eugene, near where he lives, strangers at the supermarket and gas station have invited him to go fuck himself. Grower websites have posted the latitude and longitude coordinates of his home, and his office has been burglarized. From the pattern of door and room alarms that were triggered, it looked like the intruder headed straight for his desk. “That means someone was probably watching where I sit,” he says.

The worst fallout came one evening in February 2014. Gabriel and his wife Greta Wengart, who was pregnant at the time, called their two dogs in from the backyard. Nyxo, a 100-pound black lab mix, had been barking at something across the fence. He was a gentle giant they had adopted from a local shelter ten years before, after he had been shot at, tossed from a truck, and left for dead. Nyxo seemed sluggish as he went to sleep. In the middle of the night they heard him throwing up.

Early the next morning Nyxo started drooling and collapsed. Gabriel rushed him to the vet, but the dog slipped into a coma. That afternoon he had to be put down. Mourad helped with the necropsy—“one of the hardest things I’ve ever had to do.” He found Nyxo had been poisoned with brodifacoum, an anticoagulant rodenticide. A reward of $20,000 still has not brought in a single lead. Gabriel and Wengart’s daughter was born two weeks later.

Since then Gabriel has surrounded his house with high-def cameras and motion-sensor lights. He has learned to live with one eye over his shoulder, always scanning for suspicious cars or strangers. “I’m not being ignorant,” he says. “I have to be perceptive, for my family’s sake.”

Wengart is also a biologist, and serves as the IERC’s assistant director. She and Gabriel work closely on grow sites and other projects. “I worry about him less than I used to,” she says. “When he’s doing ground entry, that’s the only time I get nervous.” But that’s the only way to get certain kinds of information, by questioning captured growers, and the only way to make sure no one on the entry team stumbles upon anything toxic. The couple started out working together on busts, but now they try to take turns. Not being in the same place at the same time is both safer and more efficient. “It’s definitely a conscious choice,” she says.