Volunteers have to sign the group’s standard operating procedure and rules of engagement setting out the legal framework for any encounter with border crossers in the rugged back country — part of the Border Patrol’s Tucson sector, where agents last year seized nearly 600 tons of marijuana and made more than 120,000 arrests.

“We don’t violate anybody’s rights. I’m pretty sure you have to be a citizen in the first place to have rights in this country, but … we don’t treat anybody badly,” Foley said. “We don’t pistol-whip them, beat them, do any of that stupid shit. We treat them as human beings.”

Should they encounter a group of suspected undocumented migrants, volunteers may detain them, conduct a cursory search for weapons and inspect them for any medical needs while they call Border Patrol to effect an arrest, according to the group’s procedures.

If volunteers encounter armed border crossers, the AZBR members order them to lower their weapons and put their hands up, while keeping guns at “the low ready,” with fingers off the trigger, prepared to use deadly force if necessary, Foley said.

“Everyone knows what a racking 12-gauge shotgun sounds like. If you don’t, you’d better learn what it sounds like, because if somebody does it to you, you’d better stop dead in your fucking tracks,” he said, adding that he had not yet had to do so on a stakeout.