In a historic decision, a Guatemalan court convicted former military dictator José Efraín Ríos Montt on 10 May of genocide and crimes against humanity for the massacre, torture, rape and forced displacement of indigenous villagers during counter-insurgency campaigns in the early 1980s. The verdict is unprecedented: never before has a national court found a former head of state guilty of genocide. It sends a powerful message: no one is above the law and everyone - including indigenous communities long marginalized by discrimination and poverty - has the right to seek justice in the courts.

That the trial took place in Guatemala - a country where, as Crisis Group has reported, impunity was long the norm for abusive or corrupt officials, organised crime bosses and common criminals alike - is testament to the courage and persistence of judges, prosecutors, human rights defenders and members of the Maya-Ixil community themselves. Speaking through translators, witnesses recounted harrowing tales of murder, gang rape and flight after the army torched their villages and fields. Although truth commissions led by the UN and the Catholic Church collected similar testimonies in the 1990s, coverage of the trial allowed many Guatemalans to hear and read for the first time about atrocities committed during an armed conflict that began in 1960 and lasted for more than three decades.

By having the courage to testify in open court - subject to cross examination by defence attorneys - these witnesses may also encourage the victims of more recent crimes to come forward. Impunity feeds a vicious circle in Guatemala: because most crimes go unpunished, few bother to even report them. Opinion polls show that Guatemalans have little confidence in the courts or the police, who are often viewed as either ineffective or corrupt. But over the five-week trial, the country got a rare glimpse of an independent judiciary in action as the three-judge tribunal heard from about 100 witnesses, including indigenous survivors, psychologists, historians, forensic anthropologists and military experts.

The process is far from over. Ríos Montt's attorneys have motions and injunctions pending in other courts that could annul the trial. They have also promised to appeal his conviction, a process that could take months or even years. Nor is Ríos Montt the only individual targeted for prosecution as a war criminal. The tribunal acquitted his co-defendant, former director of military intelligence José Mauricio Rodríguez Sánchez, because it concluded that he had no direct command over troops. But it urged prosecutors to pursue other alleged violators. Among those now facing trial is an ex-guerrilla commander charged with massacring civilians in the village of El Aguacate.

Critics contend that these prosecutions will re-open old wounds in a country where tension is already high in many rural areas over mining and access to land or electricity. But failing to prosecute those responsible for political repression in the past would only perpetuate the cycle of impunity that encourages criminal violence today. President Otto Pérez Molina should continue to support the efforts of Attorney General Claudia Paz y Paz, recipient of Crisis Group's Pursuit of Peace Award in 2011, to bring criminals to justice, regardless of their military rank, political power or economic might. Pérez Molina has promised to respect the judicial process. By holding to that promise, he will demonstrate to the world - and more importantly to his fellow citizens - that Guatemala is no longer a country where criminals can operate without fear of prosecution.