NACO - A trail of red dots appears on the computer radar screen.

Border Patrol Agent Orlando Rocafort, whose flatbed truck sits atop a peak overlooking a stretch of the U.S.-Mexico border, leans in for a closer look. He slides his computer's mouse over the red dots near the border between Naco and Douglas, and clicks.

A whizzing sound comes from the bed of the truck. A pair of mounted cameras rotates, facing southeast. Inside the truck, black-and-white images come into focus on a monitor at Rocafort's right. The thermal night camera shows what appears to be several people carrying backpacks near the border fence.

Rocafort picks up his radio and tells agents where to find the suspected illegal immigrants.

On this windy and cool May evening in Southeastern Arizona, Rocafort is running one of 38 "mobile surveillance systems" the Border Patrol uses on the Southwest border. The truck-mounted systems give agents the ability to scan at least six miles of border using ground surveillance radar, Doppler radar and infrared day-night cameras.

The Doppler radar system alerts operators when something moves in the area covered, a key reason the technology is so valuable, Rocafort said.

"With these systems, we've pretty much shut down traffic in some areas," said Rocafort, who trains others on how to operate the systems. "If you have an experienced operator, I've seen guys work seven, eight groups at a time."

These systems, which cost about $800,000 each, have gained widespread popularity in the past two years among agents, Border Patrol leaders and politicians, for two simple reasons - they work, and they are available now.

The units give the agency a small-scale version of what officials hoped the SBInet "virtual fence" networks would offer - the ability to detect and identify who is crossing the border, and where.

The Boeing Co.-led SBInet program has been plagued by glitches and delays since the program was launched in 2006. Despite allocations of $1.6 billion, the program's promised technology is still not available to the Border Patrol, a May report from the Government Accountability Office found.

Two grids along 53 miles of border in Southwestern Arizona are up, but not yet working.

The problems prompted Homeland Security Secretary Janet Napolitano to order a reassessment of the program in January and freeze future funds in March. When she announced the freezing of funds, she also reallocated $50 million from stimulus funds to buy commercially available, stand-alone technology.

More than half of that - $31.7 million - is scheduled to buy mobile surveillance systems like the one Rocafort uses. It's unclear how many will be bought because federal officials are still acquiring them, said Steven Cribby, a Border Patrol spokesman in Washington, D.C.

But at $800,000 each, it should be enough to buy about 35 to 40. That would double the 38 already in use along the U.S.-Mexico border, 20 of which are in the Border Patrol's Tucson Sector.

Part of broader plan

The systems are part of Homeland Security's Secure Border Initiative, a multi-billion-dollar program launched in November 2005 to secure the borders and reduce illegal immigration, said Rich Stana, director of homeland security issues at the Government Accountability Office.

The initiative, which has been allocated $4.5 billion since it originated, has paid for border fencing, roads and lighting as well as the development of SBInet "virtual fences."

Up until now, the mobile surveillance systems have been a minor part of the plan, receiving only a fraction of the funds: $9,000 in 2007, $187,000 in 2008 and $130,000 in 2009, Stana said.

The plan was to link the truck units with the SBInet "virtual fence" systems, but that hasn't happened.

The mobile systems are the only technology agents have received from the initiative that actually works, said Brandon Judd, vice president of Local 2544 of the National Border Patrol Council, the agents' union.

Agents have been using more basic mobile surveillance systems for more than a decade, Judd said. The current systems are an advanced version of the original units.

Improving on technology that works is more useful to Border Patrol agents than spending time and money trying to create new, grandiose technology such as the virtual fences, Judd said.

"Technology is a good thing as long as we are spending money on what we know is going to work," Judd said. The mobile systems are nothing new, "but what they've done is make them a lot better than they used to be."

Group spotted

Border Patrol agent Mike Estrada is deep in the brush trying to find the group Rocafort spotted on the mobile surveillance system.

He's not using his flashlight to avoid being spotted, and is taking direction from Rocafort via radio. Rocafort is following the group's movement on the thermal camera.

"About 20 yards to the east," Rocafort says.

"They're laid up in that heavy brush just south of you," Rocafort says.

Farther north, another agent drives back and forth on an east-west road to deter the group from going farther.

An hour after Rocafort spotted the group, about 10 people emerge from the brush and make a dash to the border fence between two agent vehicles. They climb back into Mexico.

"It's a success because even though we weren't able to apprehend them, they are not in the United States," says Border Patrol Agent Colleen Agle.

In the Tucson Sector alone, the systems forced 12,000 illegal immigrants to turn back into Mexico through the first seven months of fiscal year 2010, Agle said.

In that same time, Border Patrol figures show, the mobile surveillance systems have also led to:

• 29,000 apprehensions of illegal immigrants, nearly 20 percent of the 148,283 apprehensions made sector-wide.

• 112,600 pounds of marijuana seized, 18 percent of the 622,530 pounds seized sector-wide.

The success has politicians including mobile surveillance systems in their calls for more border security, which have increased in the wake of the March 27 killing of longtime Cochise County rancher Robert Krentz.

In their 10-point border-security action plan released in April, Republican U.S. Sens. John McCain and Jon Kyl called for the government to substantially increase the number of mobile surveillance systems along the Arizona-Mexico border.

The Arizona Cattlemen's Association included a request for more systems in its 18-point "Restore Our Border" plan issued in mid-April.

And in a letter sent to President Obama on March 30, Rep. Gabrielle Giffords, D-Ariz., asked that more systems be sent to areas "currently under siege by smugglers."

She wrote: "Reports from ranchers and Border Patrol agents indicate that, where these units have been set up, the smuggling traffic dramatically decreases and apprehensions increase."

On StarNet: Read more about border- related issues in Brady McCombs' blog, Border Boletín, at go.azstarnet. com/ borderboletin

Progress of Arizona 'virtual fences'

Homeland Security Secretary Janet Napolitano froze future funds for SBInet virtual-fence projects in March until a reassessment of the program is completed, but work continues on two tower systems along about 53 miles of border in Arizona.

Both systems - the 17-tower "Tucson-1" system along 23 miles flanking Sasabe and the 12-tower "Ajo-1" system along 30 miles of border near Ajo - are built but haven't yet passed government testing required to hand the systems over to the Border Patrol for use. Both are expected to be up and running this year, says a May report from the Government Accountability Office.

But delays have plagued the program, and missed deadlines have become the norm. Lingering issues include "instability of the cameras and mechanical problems with the radar at the tower, and issues with the sensitivity of the radar," the GAO report found.

About $1.6 billion has been allocated to SBInet in the past four years, the GAO report found.

Contact reporter Brady McCombs at 573-4213 or