Guatemalan dictator José Efraín Ríos Montt, convicted of committing acts of genocide earlier this month, will not be headed to prison. For the time being he'll return to house arrest, after the country's highest court determined that the conclusion of his unprecedented trial be thrown out.

Montt held power in Guatemala between 1982 and 1983, during which time he was accused of ordering troops to massacre indigenous Mayans. On May 20, he was convicted of that crime and sentenced to 80 years in prison, a de facto life sentence for the 86 year-old. Shortly after the trial — a first in Central America — he was transferred to a prison hospital.

Now, he's likely to head home under guard. In essence, the Constitutional Court rewound the trial, which concluded on May 20, back one month. The Times reports on the decision.

The court did not invalidate the entire trial, which began on March 19. Instead, the court ordered that the proceedings be rolled back and reset to April 19, when a complex decision by another judge sent the trial into disarray, causing a brief suspension.

By April 19, the tribunal had heard all of the prosecution’s case and most of the defense’s. That testimony still stands. But the court’s ruling invalidated everything after that date.

To some extent, the turmoil is the Constitutional Court's own fault. On April 18, one of its judges ruled that the entire trial be restarted. The next day, the judges hearing the trial asked the Constitutional Court if it could continue; on April 30, it did.

How the trial proceeds from this point on is still not entirely clear. Nor is it clear what the implication might be for Montt's co-defendant José Mauricio Rodríguez Sánchez. He was acquitted during the trial, raising the question of whether or not he'd be re-arrested.

BoingBoing's Xeni Jardin, who covered the trial in person, reinforces that the next steps are unclear. She makes clear, too, that the setback is greater than the legal chaos.

It is an unimaginable blow to each of the Ixil Maya victims, and others, who suffered abuses during the US-backed military dictator's 17-month reign.

About 100 Ixil survivors testified during the trial.