ONE afternoon eight months ago in the mountains of eastern El Salvador, Rosario Sánchez peered into a pit where forensic experts were at work. They were unearthing human remains—two skinny leg bones, several ribs and two halves of a skull. One held up a thin chain hardened with blood and soil. Ms Sánchez gasped. “My sister loved that necklace,” she said.

Over three days in December 1981 soldiers from the Salvadorean army, who had been trained by the United States, machinegunned hundreds of unarmed men, women and children in the village of El Mozote and surrounding hamlets. It was the worst atrocity committed during the 12-year-long war between leftist guerrillas and El Salvador’s right-wing government, in which some 75,000 Salvadoreans died. No one has been punished for the massacre, and almost no one has been held to account for any other human-rights crime committed during the conflict. An amnesty law in 1993 shielded perpetrators on both sides from prosecution, and helped make a political settlement possible.

As the exhumations in La Joya, near El Mozote, show, the amnesty is being called into question. El Salvador’s Supreme Court is considering a constitutional challenge to it. The court ruled in 2000 that the amnesty does not apply to violations of “fundamental” rights, but left it to judges and prosecutors to decide which crimes are grave enough to qualify.

Some human-rights advocates argue that impunity for war crimes is one reason why El Salvador has the world’s highest murder rate, although other factors, such as the lack of economic opportunity, undoubtedly also play a role. “The same system that was incapable of investigating human-rights violations has found itself incapable of confronting post-war violence and crime,” says David Morales, El Salvador’s Human Rights Ombudsman.

The country’s post-war reconciliation was in many ways exemplary. Both sides disarmed, the army shrank and the security forces were transformed into a civilian police. After the war’s end in 1992, a UN Truth Commission spent six months investigating “serious acts of violence”. It registered 22,000 complaints, 85% of them against the armed forces, paramilitary groups and right-wing death squads. Their left-wing foe, the Farabundo Martí National Liberation Front (FMLN), was accused in 5% of the cases. The commission’s report blamed the army’s elite Atlacatl battalion for the murder of six Jesuit priests in 1989 and for the El Mozote massacre, among other findings.

For the leaders of post-war El Salvador, the commission’s revelations were justice enough. Five days after its report was published the government enacted the amnesty law. It is one of the few things on which both leftist and conservative politicians agree. “We chose peace over justice,” says Mauricio Vargas, a retired general who represented the army in the peace process. Without the amnesty, “the whole building comes crashing down.” Salvador Samayoa, who represented the guerrillas, warns that if the left demands trials of former military officers the right will go after ex-guerrillas, including the president, Salvador Sánchez Céren. He was a commander of the FMLN, which became a political party after the war.

Other countries in Latin America, perhaps surer that their democracies are stable, are testing whether justice in the courts will jeopardise peace. In Guatemala, a UN–backed commission to investigate corruption has strengthened the justice system. That helped make it possible for prosecutors to bring several human-rights cases, including against the former dictator, Efraín Rios Montt. Colombia, which is close to a peace agreement with leftist FARC guerrillas, whom it has been fighting for more than 50 years, will not offer a general amnesty, although just how criminals will be punished has yet to be decided.

Not even past

The United States, once a haven for criminals from Latin America’s wars, has changed its stance. It is seeking to deport José Guillermo García, a former Salvadorean defence minister, on charges that he bears responsibility for the El Mozote massacre and the murder in 1980 of three American nuns and a lay worker. A proposed $750m aid package for three Central American countries sets as one condition that governments must prosecute soldiers and police officers suspected of human-rights violations, including past war crimes.

In El Mozote daily reminders of the atrocity keep alive the demand for an accounting. One farmer, digging the foundation for a new house, recently uncovered skeletons of 15 of his relatives. He recognised his mother’s skull from the crown on a tooth. Still isolated and poor, the village trades on its tragedy: locals sell mementos of the massacre at stalls near the site and jostle to relate the story to tourists in exchange for small tips.

The demand for justice is chipping away at El Salvador’s amnesty. In 1990 relatives of the victims, helped by Tutela Legal, a human-rights group, filed a suit at the Inter-American Court of Human Rights. Twenty-two years later the court ordered El Salvador’s government to investigate the massacre, punish the culprits and compensate victims’ relatives. El Salvador’s then-president, Mauricio Funes, admitted the state’s responsibility and, weeping publicly, begged forgiveness. A trickle of aid to El Mozote followed: a clinic, computers for the school and road repairs.

But the messy conduct of the exhumation shows how little official enthusiasm there is for investigation and punishment. The human-rights unit of the attorney-general’s office, which promised in 2013 to investigate El Mozote and seven other massacres, put in charge of the dig a systems engineer with no formal training in excavation. Work started in the rainy season, when floods threatened to damage DNA evidence. The villagers received no advance notice, and at first no counselling from psychologists. Instead of healing wounds, the investigation reopened them, their lawyers said.

The intervention of the government’s forensics agency, the Legal Medicine Institute, improved matters, and showed that the government’s apparent hostility to the investigation is not uniform. The agency assigned three Canadians—two anthropologists and an archaeologist—to help with the excavation. The attorney-general’s office sought to undermine the three women, claiming that they were unqualified. The director of the human-rights unit, Mario Jacobo, declined to comment on the conduct of the excavation. He recently lost responsibility for it. A judge suspended it after two weeks of digging, and said it should resume under the direction of the Legal Medicine Institute. Work is likely to restart in early 2016.

Although opinion may be shifting, many Salvadoreans are loth to unpick an amnesty that has served the country well in many ways. There is speculation that the Supreme Court will strike a compromise: uphold the amnesty law, but compel prosecutors and judges to pursue violations of fundamental rights, rather than leaving the decision to them, as its earlier ruling did. On November 23rd six members of the United States House of Representatives sent a letter to legislators in El Salvador urging them to choose a “new attorney-general focused on defeating corruption and organised crime”. This was widely interpreted as a slap at the incumbent, Luis Martínez, who hopes to be re-elected by El Salvador’s Congress.

The families of El Mozote hope that pressure to investigate and punish today’s crimes will lead to prosecutions for past atrocities. In December laboratory tables in the San Salvador headquarters of the Legal Medicine Institute were covered with the bones of Ms Sánchez’s murdered relatives. Brittle and brown, they lay among bundles of tattered clothing and stacks of rusted coins. Other tables displayed larger, lighter-coloured bones. They belonged to unidentified victims of recent gang violence. The government—and probably still most Salvadoreans—think going after today’s murderous gangs should be the priority: 95% of murders are unsolved. To the survivors of El Mozote, both groups of victims are entitled to the same justice.