Random Act or Ambush? Feds Probe Shooting of U.S. Agents in Mexico

Feb. 16, 2011— -- President Obama today pledged that the U.S. government would do everything in its power to bring to justice Mexican gunmen who killed a U.S. special agent and wounded another in a brazen roadsize attack Tuesday afternoon.

Obama offered the assurances during a call to the parents of slain Immigration and Customs Enforcement agent Jaime J. Zapata this morning, adding that their son's "service and sacrifice will be remembered."

Zapata, 32, a four-year ICE veteran based in Laredo, Texas, had been stationed at the U.S. Embassy in Mexico City as part of a human smuggling and border security enforcement task force.

He and another agent, Victor Avila, were travelling on a rural highway between Mexico City and Monterrey in an armored Chevrolet SUV Tuesday when they were apparently stopped at an unofficial checkpoint outside the town of Santa Maria del Rio.

Gunmen opened fire, spraying the SUV with bullets. Zapata was killed, and the other agent, who was hit in the arm and leg, was airlifted to a Mexico City hospital. He has since returned to the U.S. where he's recovering in a Texas hospital.

Federal investigators descended on Mexico today to assist local authorities in the hunt for the unidentified gunmen, as officials in Washington announced the FBI would lead a special joint task force between the Department of Homeland Security and Department of Justice to ensure the assailants are caught.

Homeland Security Secretary Janet Napolitano condemned the attacks as "unconscionable crimes" and said that U.S. officials are "working closely with Mexican authorities."

"Let me be clear: any act of violence against our ICE personnel -- or any DHS personnel -- is an attack against all those who serve our nation and put their lives at risk for our safety," she said in a statement. "The full resources of our department are at the disposal of our Mexican partners in this investigation."

It's unclear whether the shooting was random or whether the agents were targeted, but there is speculation it was tied to raging drug-related crime across Mexico that has left 35,000 people dead since December, 2006.

The state of San Luis Potosi, where the attack occurred, has experienced occasional outbursts of violence as cartels have battled for territory and used aggressive tactics to steal cash, weapons and vehicles.

Texas missionary Nancy Davis was shot and killed last month in northern Mexico while driving a Chevrolet pickup truck which investigators believed the attackers wanted to steal. The U.S. special agents' blue Suburban might have been a similar target.

If the agents were ambushed, it could signal a reaction to stepped-up pressure by U.S. and Mexican authorities on cartel activities.

The U.S. has pledged $1.4 billion to help equip and train Mexican law enforcement to combat the cartel-fueled violence in recent years.

And in the past two years alone, officials have seized $282 million in illegal currency, 7 million pounds in illegal drugs, and 6,800 illegal weapons flowing between the U.S. and Mexico, representing significant increases over prior years.

"As they see that U.S. involvement grows more and more and more, the temptation on their part to start going after Americans will also grow," said former Mexican Foreign Minister Jorge Castaneda of the cartels.

Mexican Violence Impacts Americans

Zapata's murder is the highest-profile Mexican incident involving a U.S. government agent since the kidnapping, torture and murder of undercover Drug Enforcement Administration agent Enrique Camarena in 1985.

But it is also the latest example of violence against Americans in or near Mexico in recent months.

U.S. Border Patrol Agent Brian Terry was shot and killed in a gun battle with Mexican bandits in the Arizona desert in December just 10 miles north of the Mexican border.

In 2009, Border Patrol Agent Robert Rosas was killed just inside Tecate, Mexico, near San Diego, Calif.

And, American David Hartley was allegedly shot and killed by Mexican pirates in September on Falcon Lake along the Texas-Mexico border.

ABC News' Devin Dwyer and Pierre Thomas and The Associated Press contributed to this report.