The danger signs had been mounting. The U.S. Consulate in Ciudad Juarez recently shut down for a bomb threat (which proved false). Federal police guards were redoubled. Officials working at the diplomatic mission saw their movements being gradually restricted, some parts of the city deemed too dicey to frequent.
But the Americans leaving a weekend child's birthday party probably made the same calculations that many people living in Mexico make. It was broad daylight. We'll be traveling on major roads. It is probably safe enough.
Lesley Enriquez, a U.S. consular official, and her husband, Arthur H. Redelfs, were driving home to El Paso, just across the border, when suspected drug gangs intercepted their car and shot them to death Saturday afternoon. Their baby daughter, dressed in pink and crying in the back seat, survived unharmed.
At almost the same time, in a separate but similar car leaving the same party, Jorge Alberto Salcido was also shot to death. Two children with him were injured. Salcido was a Mexican citizen married to a Mexican who works at the consulate.
The drive-by slayings marked a rare attack on a U.S. official in Mexico's raging drug war, which has claimed at least 18,000 lives in slightly more than three years.
"The tragedy of this weekend just underscores how severe and significant a danger this represents to Mexico, to the United States, to the hemisphere," State Department spokesman P.J. Crowley said in Washington.
As the FBI joined the investigation Monday, Mexican authorities said they believed the victims were targeted but that it remained to be determined why. U.S. officials were cautious.
"At this point, we don't have information that says they were targeted because of their employment at the U.S. Consulate," said Andrea Simmons, an FBI spokeswoman in El Paso. "It's a possibility, but so far nothing has indicated it was directly related to their employment. . . . In the past, we have had cases that turned out to be mistaken identity."
If traffickers deliberately attacked U.S. diplomatic personnel, it would mark a significant departure in their tactics. Of paramount importance to traffickers is the ability to successfully conduct the business of transporting drugs. It stands to reason that most probably figured, at least until now, that attacking American officials would attract too much heat.
"This was meant as a message: We know who you are and you are vulnerable," said Alberto Islas, a security analyst based in Mexico City. He said traffickers may have been reacting to increased involvement of U.S. officials in Mexico's drug war, especially in the sharing of intelligence that has led to the capture of several high-profile suspects.
But such a move would be risky for traffickers if the killings spur the Obama administration into tougher actions against the drug trade, in support of Mexican President Felipe Calderon's military-led offensive against cartels.
State Department officials said they were not aware of specific threats against any consular employees.
But the signs of trouble were apparent, here and elsewhere along Mexico's northern border with the United States. In Reynosa, in neighboring Tamaulipas state, the U.S. Consulate was closed last month because of raging gun battles. The consulate in Monterrey has come under grenade attack.
The consulate in Ciudad Juarez was closed Monday for a holiday and will remain closed Tuesday, U.S. officials said, in a gesture of mourning and for a security review. On Monday, under Ciudad Juarez's heavy gray skies, the consulate loomed seemingly deserted behind high concrete walls. Mexican federal police in masks stood guard. The American flag was at half staff.
Before the killings, the State Department had decided to allow consulate employees in six northern cities to send their families out of the country, officials said. That decision was made because of growing safety concerns among American employees and security officers.
Mexican officials said they suspected the Aztecs gang in Saturday's slaying. The gang is tied to the Juarez cartel, which has long controlled trafficking and other illicit business in this city but which is now fighting an attempted takeover by the powerful organization based in the Pacific drug-producing state of Sinaloa.
Ciudad Juarez Mayor Jose Reyes Ferriz, acknowledging such crimes are rarely solved, said he welcomed help from the FBI and other U.S. officials. "The fact that U.S. diplomatic personnel are attacked adds to a situation that is already critical," he said.
Ciudad Juarez long ago earned the title of Mexico's deadliest city, and one of the deadliest in the world. Despite the deployment of more troops and police, about 500 people have been killed this year -- 31 last weekend, including Enriquez, Redelfs and Salcido.
**Times staff writers David Savage and Paul Richter in Washington and Richard Marosi in San Diego contributed to this report.