Manhunt underway for killer of Border Patrol agent

• Manhunt underway for suspects who shot two agents near Naco, Ariz.
• One agent killed; other agent airlifted to hospital
• Last agent fatally shot on duty was Brian Terry in 2010

WASHINGTON -- Federal and state authorities launched a vast manhunt along a remote part of the Arizona-Mexico border for three to four suspects in a Tuesday shooting that left one Border Patrol agent dead and another wounded.

Dozens of investigators in helicopters and on horseback were searching an area as large as 20 miles for the suspects who opened fire on the agents as they approached to check on a tripped ground sensor shortly before 2 a.m.

The Border Patrol identified the slain agent as Nicolas Ivie, 30.

Ivie and two other agents were attacked near the location where fellow Border Patrol Agent Brian Terry was shot to death in December 2010.

Terry's murder prompted congressional and Justice Department inquiries into a botched federal gun trafficking investigation that allowed 2,000 firearms to fall into the hands of Mexican drug cartel enforcers and other criminals.

Two weapons linked to that operation -- known as Operation Fast and Furious -- were found at the scene, but the weapon used to kill Terry has not been identified.

Cochise County Sheriff's Department Cmdr. Marc Denney, whose agency is assisting the FBI, said no weapons have been recovered from Tuesday's attack.

It also was immediately unclear why the suspects were in the location, a rocky corridor known for human smuggling and drug trafficking about 5 miles from the border.

"It was basically an ambush," Denney said, adding that it was possible the suspects fled to Mexico following the shooting.

"They had a little bit of a jump on us," he said. "It is very rocky terrain. We're hoping that they hunkered down somewhere close by so that we have an opportunity to find them.''

"I am deeply saddened," Department of Homeland Security Secretary Janet Napolitano said after being informed of Ivie's death on Tuesday. "This act of violence reminds us of the risks our men and women confront, and the dangers they willingly undertake, while protecting our nation's borders. We are working closely with our federal, state and local law enforcement partners to track down those responsible for this inexcusable crime, and to bring them to justice."

Republican Arizona Gov. Jan Brewer issued a statement blasting the federal government for failing to secure the border.

"Arizonans and Americans will grieve, and they should," Brewer said. "But this ought not only be a day of tears. There should be anger, too. Righteous anger -- at the kind of evil that causes sorrow this deep, and at the federal failure and political stalemate that has left our border unsecured and our Border Patrol in harm's way."

George McCubbin, president of the National Border Patrol Council, an association of 17,000 agents and staffers, said the wounded agent was recovering and the third was not wounded.

All three were on horseback when they were attacked.