MEXICO CITY -- "Excuse me, Mr. President. I cannot say you are welcome here, because for me, you are not. No one is."
The woman's voice trembled with bitterness and apprehension. She stood just a few feet away from a low stage where Mexican President Felipe Calderon, his wife, Margarita Zavala, and top members of his Cabinet were seated at a tightly controlled forum in Ciudad Juarez on Feb. 11, 2010.
"No one is doing anything! I want justice, not just for my children, but for all of the children," she went on. "Juarez is in mourning!"
The woman, later identified as Luz Maria Davila, a maquiladora worker, lost her two sons in a massacre that had left 15 young people dead during a house party in Juarez 12 days earlier.
Calderon initially dismissed the victims as "gang members," more cogs in the machine of violence that by then was terrorizing every sector of what was once Mexico's most promising border city. But news reports quickly revealed that the victims of the Villas de Salvarcar massacre were mostly promising students and athletes.
They died only because they were in the wrong place at the wrong time: Juarez hitmen had been ordered to kill everyone at the party because it was believed that rival gang members were in attendance.
"I bet if they killed one of your children, you'd lift every stone and you'd find the killer," Davila said to the president as the room fell silent after her interruption. "But since I don't have the resources, I can't find them."
Calderon and Zavala remained silent, frowning.
"Put yourself in my shoes and try to feel what I feel," the mother continued. "I don't have my sons. They were my only sons."
It was a searing, unscripted moment in a presidential term that was abundant with them.
In his six years in office, a term ending Saturday with the swearing-in of his successor, Enrique Peña Nieto, Calderon's government built bridges and museums, expanded healthcare and led major international meetings on climate change and development. But for the many achievements, the Calderon years will probably be remembered as the bloodiest in Mexico's history since the Revolutionary War a century ago.
Civilians were mowed down by masked gunmen at parties and funerals. Journalists, mayors, human rights activists, lawyers and police commanders from small towns to big cities were shot while sitting in their cars or going on errands. Regular citizens, from small-business owners to oil workers, were snatched from homes or offices and never heard from again.
While drugs continued to flow north and U.S. government weapons and cash laundered by major global banks flowed south, the Calderon security strategy remained basically unchanged over the years. Its effect was a catastrophic expansion of violence and a crime-solving rate of nearly zero.
For average Mexicans, the extreme violence seen during this sexenio -- as a six-year presidential term is called -- was psychologically and emotionally grueling, particularly for children, experts say. In many parts of Mexico, a culture of fear settled over the population.
Overall, more than 100,000 people were violently killed in Mexico during this term, government figures show. The number of those killed directly tied to the drug war may never be known, as the lines blurred between drug-trafficking violence and violence spurred by the general impunity enjoyed by the drug lords.
The national human rights commission says more than 20,000 people are missing in Mexico. Torture is also believed to be widespread nationally.
During this term, Mexican cartels also expanded their control and firepower to Central America, while clandestine anti-trafficking operations led or funded by the United States grew to unprecedented levels, as The Times reported this week. About half of Mexico's territory is believed to be under cartel influence.
Here is a rundown of some significant events and markers of Mexico's drug war from 2006 to 2012 -- the Calderon years.
Military campaign begins
In mid-December 2006, days after assuming the presidency in a chaotic struggle with leftists who refused to recognize his electoral victory, Calderon's government sent more than 6,700 troops -- soldiers, marines and federal police -- to his home state of Michoacan to launch his fight against organized crime.