"This is it right here, this is where the ambush occurred?" CBS News chief investigative correspondent Armen Keteyian asked Detective Juan Carlos Navarro of the Pima County Sheriff's Department.
"Yeah - this was where it happened," Navarro said.
Just before dawn on the morning of March 30th, two men were camped on a hilltop, waiting, looking to hijack a truck full of marijuana said to be moving north along an old smuggling route that cuts across Green Valley - some 40 miles from the Mexican border.
"They open fire, they shoot at least 65 times," he said. They used automatic weapons.
"They are using AK-47s, yes," he said.
Twenty-three rounds blistered the Ford Pick-up, a truck packed not with drugs but with people, 25 illegal immigrants. Two were left dead and three wounded.
It was the work of so-called Bajadores, modern-day desert bandits.
He said rival gangs of heavily-armed bandits are increasingly at war all across his county - ripping off valuable loads of drugs and human cargo. The illegals are often held hostage until families back home pay thousands of dollars in ransom.
"Over the course of the last year it's become a lot more violent," said Sgt. Jim Murphy, who heads the Pima County border crimes unit. "What bleeds across here spreads out across the whole United States."
The border crimes unit is a special squad formed a little over a year ago to crack down on the latest - and most violent twist - in the smuggling trade.
Five nights a week, just seven deputies play a cat-and-mouse game with the desert bandits across 9,000 square miles of rugged terrain.
Two to three hundred bodies are recovered out here every year - a dozen in recent months dying at the hands of bajadores.
"It worries me for the retirement people because they actually come to Green Valley to retire and now they have to deal with this," Murphy said.
Ambushes and automatic weapons - creeping ever closer to the idyllic lives of retirees.