Word has come from the Peck Canyon Corridor of another deadly shooting in Arizona's borderlands.

This latest episode took the life of Border Patrol agent Brian A. Terry. Details are sketchy as of now, but it appears Terry came upon a group of presumed smugglers at Peck Wells, which is part of Peck Canyon, when the shooting occurred.

The Border Patrol's public-information office in Tucson confirms that at least four suspects are in custody, and one more is being pursued. A massive manhunt is underway as Border Patrol and other law-enforcement agencies try to apprehend the suspect, believed to be trying to flee into Mexico.

A rancher in the southern part of the Peck Corridor, reached moments ago, tells me that law-enforcement vehicles have been roaring up and down Ruby Road all morning. "The hills around my house are crawling with agents," he says. "They're all over the place"

Peck Wells is on Coronado National Forest land about 2 miles west of David and Edith Lowell's Atascosa Ranch home. The Lowells played a prominent role in my recent Tucson Weekly cover story on the Peck Canyon Corridor.

The piece drew a parallel between the increasing violence in this area north and west of Nogales with what had been happening in the Chiricahua Corridor, above Douglas, prior to the March 27 murder of Rob Krentz.

The killer in that case is still at large. But investigators followed what were believed to be the killer's tracks into Mexico, and Cochise County Sheriff Larry Dever says he has reason to believe the killer was a drug scout.

One of my Chiricahua Corridor articles revolved around Louie Pope, who agreed to tell his story, and allow his name to be used, in spite of the clear danger.

Louie said: "I really expect to get death threats from this, but we have the opportunity to tell an important story about what's happening out here, and we need to do it before something bad happens."

Krentz was killed six months later.

About the Peck Corridor, last month's story said: "Can the violence be stopped before we have another borderlands tragedy involving an American citizen or a lawman?”

Sad to say, we can't.

The Peck Corridor story reported that there had been at least five shootings on the Lowells' Atascosa Ranch in the past year.

Three of these were sniper-style shootings in Peck Canyon itself. There was another sniper-style shooting—this of a Border Patrol agent, wounded in the ankle—in Ramanote Canyon in December of 2009. Ramanote Canyon is about 2 miles from Peck Wells.

The story asked the question: Is it safe for American citizens to go onto this public land to hunt, hike and camp?

We got an answer shortly after the story ran, when gunmen menaced a group of quail hunters in the Peck Corridor, the bad guys firing shots over the hunters' heads as they fled.

And at a citizens' meeting at Border Patrol HQ in Nogales just last night, rancher Dan Bell told me of an episode that occurred along Ruby Road within the past week.

Immigration and Customs Enforcement agents were chasing smugglers along Ruby Road, the druggies heaving their bales out the back of the truck at the pursuing ICE vehicle.

Janet Napolitano—who keeps telling us the border is just fine, nothing to see here, move along—should be put under hot lights over the Terry killing.

She needs to explain why she thinks it's safe for American citizens to venture onto this Coronado National Forest land. Would she go there herself? Would she take her family, her dog? Or would she go only with a heavily-armed security detail?

From his ranch headquarters this morning, David Lowell says: "I feel bad about the really lousy job our government is doing—not Border Patrol, but the politicians. If the same Border Patrolman had shot first and killed the (presumed) Mexican that killed him, he'd probably have a ticket to go to prison. It's a really dumb way to try to protect our southern border.

"The rules of engagement need to be changed," Lowell continued. "We should do whatever we can to allow the Border Patrol to terrify the Mexican criminals, instead of vice versa."

Lowell says he spoke this morning with a Border Patrol agent and a friend from the Forest Service.

The agent told him the shooters were likely border bandits, although that is unconfirmed, and we don't know which side of the line they're from.

The forest service man told David this might not be a good day to go out working cattle on horseback.

In other words, American citizens have to hunker down, watch their backs, hope for the best.

"Edith and I just had a discussion, and we agreed to keep our doors locked," says David. "And she might move her shotgun from under the computer table to the top of it."

We shouldn't have to keep enduring horrors of this type any time of year, but they're especially difficult at Christmas. Keep Brian Terry and his family in your thoughts and prayers.