‘They know who to choose’Stacy Zinn spent her first four years with the Drug Enforcement Administration in El Paso, Texas, where she investigated Mexican cartels. Are there drugs in Montana?’” recalled Zinn, who retired from the DEA in October after 23 years. It was one of the few states that hadn’t been a focus of Mexican cartels, Zinn said, but that soon changed. Stacy Zinn, Montana's former DEA resident agent in charge, in Billings. “Just like any other prey predator situation — that’s how it is.”The drug crisis has been felt most acutely on Montana’s Indian reservations.