A suspect in the killing of a U.S. Immigration and Customs Enforcement agent told soldiers Wednesday the attack was carried out by a group of Zetas drug gang gunmen who mistook the agent's SUV for a vehicle used by a rival gang, the army said.
Julian Zapata Espinoza — known by the nickname "El Piolin," or Tweety Bird, apparently because of his short stature — was captured along with five other suspected Zetas members during an army raid Wednesday on gang safehouses in the northern city of San Luis Potosi, near where ICE agent Jaime Zapata was shot to death and fellow agent Victor Avila was wounded Feb. 15.
"That event (the shooting) occurred because of the characteristics of the vehicle, given that they (the suspects) thought it was being used by members of a rival criminal group," an army spokesman, Col. Ricardo Trevilla, said.
The two agents were traveling in a Chevrolet Suburban. Mexico's drug cartels have frequently set up roadblocks and ambushes to steal large SUVs and pickups, vehicles they like to use.
Trevilla said military intelligence officers had identified Zapata Espinoza as the head of a cell of Zeta gang members in San Luis Potosi since early December, when raids in the area turned up other alleged gang members.
Zapata Espinoza and the five others arrested Wednesday were presented to journalists Wednesday night. One of the men had a swollen, bruised face. Soldiers found three women and one child, and five rifles at the four houses raided, authorities said.
San Luis Potosi, en route to Mexico City, is at the center of a power struggle between two rival drug gangs, the Zetas and the Gulf Cartel.
U.S. Rep. Michael McCaul told Texas Senate members Wednesday that one suspect is Jesus Rejon, a former corporal in an elite Mexican army unit who defected to the Zetas. It was not clear whether Rejon was in Mexican custody.
Rejon, 34, is wanted by Mexican and U.S. authorities. The U.S. State Department has offered a reward of up to $5 million for his capture.
The White House said President Barack Obama called President Felipe Calderón to thank him for Mexico's efforts in the case. The statement noted that Calderon would be at the White House on March 3.
Zapata, 32, and Avila were attacked when gunmen forced their sport utility vehicle off the highway. Avila was shot twice in the leg and is recovering in the United States.
U.S. Homeland Security Secretary Janet Napolitano and U.S. Attorney General Eric Holder attended Zapata's funeral Tuesday in his hometown of Brownsville, Texas. Both vowed to continue helping Mexico in its war against drug cartels battling for lucrative trafficking routes into the United States.
The Homeland Security and Justice Departments formed a joint task force led by the FBI to help Mexico find the killers.
State Department spokesman Charles Luoma-Overstreet praised Mexico for the suspect's arrest, underscoring Washington's strong public support for Calderon's crack down on drug cartels despite a growing death toll of more than 34,000 since December 2006.
"We look forward to a judicial process that ensures justice is served," he said. "Effective cooperation serves the interests of both countries," he added.
Escalating violence in oil-producing Mexico, a key U.S. trade partner, has caused alarm in Washington, which is providing $1.3 billion in funding and training for Mexico.
The two countries say cooperation is better than ever and U.S. intelligence is believed to have played a major role in the killing or capture of several top drug bosses.
But in an interview published this week, Calderon lashed out at U.S. intelligence services, saying they were too busy competing with one another to be effective.
U.S. law enforcement agencies have said they are working with Mexican authorities to investigate the attack on the agents but it is not clear if they were specifically targeted.
Officials have not said which of Mexico's drug cartels may have been behind the latest attack, although many suspect the Zetas cartel, a group led by renegade Mexican soldiers and widely seen as the most brutal of the gangs.