LAS COLINAS, El Salvador — The schoolboys went missing on a Thursday, and it took nearly three weeks for police to discover the mass grave.On July 11, a police investigator, wearing a ski mask to hide his identity, dug up the dead, the youngest age 15. One of the mothers stood weeping as the corpses were pulled out, along with curious traces of food and silverware.
General David Munguia Payes, El Salvador’s minister of justice and security, said the killings were the work of the Mara Salvatrucha, or MS-13, one of two notorious Salvadoran gangs that regularly visited schoolyards to recruit kids — often by force. The police investigator pointed at the buried remnants of a meal. The MS-13 recruiter, he said, had probably tried to persuade the youths to join the group using the usual method: a big meal with cake and soft drinks.
When they resisted, he said, they were stabbed to death.
Six months after El Salvador brokered a historic truce between two rival gangs to curb the nation’s daunting homicide rate, officials are split over whether it is actually working. In March, MS-13 and its rival, Barrio 18, vowed to end the killings and the forced recruitments in exchange for better conditions for incarcerated gang leaders, who run their operations from behind bars. The government transferred 30 bosses of each gang from the maximum-security Zacatecoluca prison, nicknamed Zacatraz, to ordinary jails, where they would impart orders to their minions on the street, purportedly to stick with the truce.
The gangs, which also operate in Guatemala and Honduras, are seeking truce talks in those countries as well.
But Carlos Ponce, an expert on crime for the Salvadoran attorney general’s office, says the truce is a sham.
‘‘It’s all a lie, the gangs continue to operate, people continue getting killed, people keep disappearing, and the gangs get stronger and stronger,’’ he said.
The Security and Justice Ministry reports that homicides in the first eight months of 2012 are already down more than 30 percent, to 1,894. For the most part, the national medical examiner’s office confirms those numbers, but the two agencies disagree on how many people are disappearing. The security ministry says 335 disappeared in the first half of the year; the legal medicine institute says the number is 1,279.
‘‘These figures are very strange,’’ Ponce said. ‘‘They say the murders are going down, they deny the disappearances, but the case of these five students is evidence that everything is still going on. It is very likely that the gangs are adopting new ways to operate.’’ Instead of leaving their victims in plain sight, he said, they are hiding them.
The justice ministry denies that assertion, saying its figures are based on investigated disappearances, whereas the medical examiner’s office is counting all reports of missing people, many of which are not verified.
‘‘Overall we haven’t had an increase. We cannot maintain strict control of the people who are registered as missing because families do not remove their reports when people reappear,’’ Munguia Payes said.
An estimated 50,000 Salvadorans belong to the street gangs that have terrified citizens and given this small Central American nation of 6 million people one of the world’s highest murder rates, behind neighboring Honduras. Though meant to stem that violence, the truce does not apply to kidnappings, extortion ,or drug sales, the core of the criminals’ business.
‘‘I think that the truce is a real farce,’’ said Max Manwaring, a professor at the Strategic Studies Institute of the US Army War College in Carlisle, Pa. ‘‘The gangs hold all the cards, and they’ve been operating out of the jails for years. The jails have become graduate schools for gang members, and the government is simply grasping at straws.’’
Like others tracking El Salvador’s truce, Manwaring doubts the homicide figures.
‘‘There is no way to count them. No way. There are many places government officials simply cannot go to investigate murders because the gangs control the territory.’’
Salvadoran security officials have been powerless to contain the violence fueled by gangs, which formed in the jails of California and spread to Central America as their members were deported by the United States.