MEXICO CITY (AFP) - There were no tears and their faces were hardened by 19 months of grief and anger as the parents of 43 Mexican students who vanished in 2014 marched in the capital.
Less than two years ago, they would have been surrounded by tens of thousands of people as they protested against President Enrique Pena Nieto's handling of the case.
But this past Tuesday - just two days after foreign experts issued a damning report accusing the government of obstructing their investigation - the protesters numbered only in the hundreds.
While the mass disappearance has tainted Mexico's image abroad, the protests have waned and Pena Nieto's administration is weathering the criticism despite falling approval ratings.
"It's a long struggle and there are few of us," said Emiliano Navarrete, holding a picture of his missing son as he walked down Mexico City's main boulevard, Reforma.
But, Navarrete said, "to shut us up they'll have to kill us." While he couldn't hide his disappointment at the low attendance, he said the "quality" of the people joining the parents was more important than "quantity." The parents traveled from Tixtla, a town in the impoverished southern state of Guerrero, where their 43 sons studied at a rural teacher college.
Prosecutors say the students were whisked away by corrupt police in the city of Iguala on September 26, 2014, after they hijacked buses to be used for a future protest.
But the experts of the Inter-American Commission on Human Rights, who were invited by the government to aid the probe at the parents' request, rejected the central conclusion in the case.
The experts said there was no scientific proof that the students' bodies were burned in a funeral pyre at a garbage dump after they were killed by a drug gang.
The mass disappearance wrecked Pena Nieto's effort to shift attention away from Mexico's drug violence and toward his ambitious economic reform agenda.
But while his popularity has dropped to 30 percent, his Institutional Revolutionary Party and its allies still managed to keep their majority in the lower house of Congress in elections last year.
Clemente Rodriguez, another desperate parent, said Mexicans probably stopped protesting because they bought the government's conclusions in the case.
With the latest protest, Rodriguez said, the families were hoping to "give a boost" to the report published last Sunday by the commission experts, who alleged that authorities tortured suspect and committed "severe irregularities" at a key crime scene.
Vidulfo Rosales, a lawyer representing the parents, said the families of the students are now hoping that "international scrutiny" can help their cause.
While the experts' mission ends on Saturday after their year-long investigation, the Inter-American Commission on Human Rights plans to create a mechanism to ensure that Mexican authorities follow their recommendations and new lines of investigation.
The experts "are putting a spotlight on our law enforcement system, which is totally dysfunctional, which tortures, which fabricates and hides evidence," said Denis Gonzalez, human rights program coordinator at Iberoamericana University.
And that makes the government "uncomfortable," Gonzalez said.
"It's not strange that society has become tired and distanced itself," Gonzalez said, noting that the country has suffered from the "psychological warfare" of a "mad war" against narcotrafficking.
Carlos Beristain, a Spanish psychologist and one of the five commission experts, said Mexicans must ensure that their government is held accountable.
"It's very important that this case is not forgotten, that Mexican society pay attention to the situation of the victims," Beristain told AFP.
"It is only this public knowledge, this monitoring of the case that will help the families feel like they are not alone, and for the case to move forward," he said.