Suitcases started piling up, unclaimed, at the depot where buses crossing northern Tamaulipas state ended their route. That should have been an early clue.
Then the bodies started piling up, pulled by forensic workers from two dozen hidden graves in the scruffy brush-covered ravines around the town of San Fernando, 80 miles south of this city that borders Brownsville, Texas.
At least 177 corpses have been recovered in the last few weeks, most of them, officials now say, passengers snatched from interstate buses, tortured and slaughtered. Women were raped before being killed, and some victims were burned alive, according to accounts from survivors who eventually overcame their fears and came forward.
The slayings have horrified a Mexican public already awash in violence and led commentators to call them "our Auschwitz" and a "Mexican genocide."
Worse yet is the realization that the killing in Tamaulipas state has been going on for months — including the brutal slayings of bus passengers — and no one, not the bus companies, nor the police, nor the officials in charge, acted to stop it.
Elida Martinez, a gray-haired woman in her 60s, was one of dozens of mothers, fathers and siblings of the missing who were waiting in the morgue here the other day to offer blood samples for DNA testing.
Two of her daughters disappeared in February, one kidnapped from the hotel in San Fernando where she worked and the other seized from her home in the middle of the night a short time later. Between them they left behind four children.
"You pray to God you won't find them here," she said. Yet the gut-wrenching uncertainty tears her apart. "You don't sleep. You can't work. You live in anguish."
After the massacre last year of 72 mostly Central American immigrants near San Fernando, the government of President Felipe Calderon promised the world, including angry Central American authorities, that justice would be done and the popular routes through northern Mexico toward the United States would be guarded.
It now appears, however, that the killings continued, and not just of immigrants but Mexican citizens and, perhaps, a handful of Americans. On Wednesday, authorities said they had rescued a group of 68 Mexicans and Central Americans who had been seized by gangsters from buses or from bus stations in the same area.
The motives behind the bus kidnappings remain unclear. Gangs may seize the passengers hoping to extort money from them, to forcibly recruit them or because they are searching for rivals.
The killings have galvanized an unusual if belated consensus, even among conservative commentators and politicians, that parts of Mexico have indeed been lost to criminal gangs such as the Zetas and the Gulf cartel that control (and are battling each other to dominate) the northeast. What does it mean, they ask, when the federal government cannot keep the nation's highways safe from brazen predators?
Even worse is the near-certainty that the police who are meant to be protectors have been involved. Among the more than 50 people arrested in connection with the latest killings are 17 local police officers accused of providing protection to the cartel gunmen believed responsible.
There is growing demand for a new government strategy and that the national Senate take the highly unusual step of dismissing the state's elected but apparently ineffective officials, a move that would also involve Calderon suspending civil rights in the region.
"If Tamaulipas is not a failed state, or a narco-state, it sure looks like one," political analyst Alfonso Zarate said. "The institutional powers are incapable of upholding the law."
Calderon has steadfastly resisted that characterization.
The top official in Tamaulipas is something of an accidental governor. Egidio Torre Cantu was elected last year, standing in at the last minute after his brother, a shoo-in for the job, was assassinated by a drug gang.
"We are prisoners in towns that we cannot leave," said Mario Alberto Alejandro, 43, who came to the morgue looking for his brother, Rigoberto, a U.S. citizen who vanished Feb. 23 on the road to Matamoros. "In whose hands are we?"
Alejandro echoed other families in saying authorities were giving them the runaround, sending relatives from the morgue to one government office after another and even in some cases to Mexico City, where most of the bodies have been taken, in part because the Matamoros morgue was full.
Alejandro said his brother Rigoberto has lived for 13 years in Texas, where he works as a forklift operator. He was in Tamaulipas to visit family, a trip he makes often.
"He never thought it would be this dangerous," Alejandro said. "There is no security."
So many families have shown up at the Matamoros morgue that locals set up a tent with chairs and a table offering coffee and water. Doors have been plastered with dozens of pictures of missing people.
Francisco Garcia's nephew Jose was on his way to Chicago from central Mexico when last heard from in early March. He was traveling with two friends, who are also missing, and all were going to join family in the U.S.
"We have not received any information, no phone call asking for ransom, nothing," said Garcia, a farmer. Too terrified to travel to Matamoros, Garcia was among scores of people who instead went to the morgue in Mexico City.
"Jose is just gone."
The Times reported in early March that several thousand people have disappeared since Calderon launched the crackdown on drug gangs in December 2006. Most vanished without a trace. Families nurse the hope that their loved ones were taken as forced laborers on marijuana farms or in meth labs. But the mass graves, here in Tamaulipas and in other parts of the country, are slowly destroying those hopes. At least 58 bodies were recovered last week from clandestine graves in Durango state.
The main bus companies that run through Tamaulipas have altered their schedules and eliminated nighttime trips through San Fernando. But they have not spoken publicly about the killings. One manager, speaking through a representative but insisting on anonymity, confirmed the existence of unclaimed suitcases but would not discuss why authorities were not informed about them.
"Maybe it's fear, or they didn't want to lose the business," said Jose Javier Saldana, a regional human rights official. "Maybe the drivers didn't report it up the chain [of management], either."
Although some of the families said the bus companies' failure to sound the alarm was unconscionable, most put the blame on authorities. Several families said authorities tried to pressure them not to speak to reporters. Furthermore, officials in three central states, Guanajuato, Queretaro and San Luis Potosi, say they have been asking the Tamaulipas government about numerous missing citizens as far back as 2009.
In the San Fernando case, in addition to the police officers, the arrested include Martin Omar Estrada, a.k.a. "El Kilo," whom authorities describe as a ringleader responsible for the latest dead as well as last summer's migrant massacre. If true, that means Estrada, who was arrested this month, and his gang continued to operate with impunity for months.
Calderon recently promised to take back Tamaulipas and flood the zone with troops. It was virtually the same promise he made five months ago.
Cecilia Sanchez in The Times' Mexico City bureau contributed to this report.