The high-profile prosecution of Rios Montt, who is accused of allowing the massacres of more than 1,700 indigenous Ixil Mayans in the early 1980s, dates back to 2012. He was convicted in May 2013, a verdict that was overturned 10 days later on procedural grounds.
A retrial, which opened Monday, was characterized by the twists and delays that marked earlier proceedings.
The accused did not show up in court. Lawyers for Rios Montt argued that the 88-year-old was too sick to attend the trial.
Rios Montt has maintained since the beginning that he did not order the massacres.
The three-judge panel rejected the motion to delay the trial because of Rios Montt's health, and ordered him to appear. Rios Montt eventually made his entrance, strapped on a gurney, covered with a blanket and wearing sunglasses.
The presiding judge, Irma Valdez, called Rios Montt's absence "unjustifiable," according to the state-run AGN news agency. Then she herself became the object of further complications.
The former dictator's defense demanded that Valdez recuse herself because of a thesis she wrote for a master's degree 10 years ago. The topic of the paper? A legal analysis of the crime of genocide as it relates to the atrocities committed during the period Rios Montt was in power.
The defense argued that Valdez had formed an opinion -- namely, that genocide did occur in Guatemala -- and therefore she could not be impartial.
The judges agreed that Valdez must recuse herself, and now the trial is suspended until an appeals court can name a new judge.
It's not controversial that a judge steps aside because of a conflict of interest, but it may have been a legal strategy by Rios Montt's lawyers to wait until the first day of the trial to make their motion. Valdez's thesis was no secret -- the thesis had been written about in the local press as early as 2003.
For observers, the legal process against Rios Montt has been both historic and confounding at times.
A long and winding road
The indictment of Rios Montt by then-Attorney General Claudia Paz y Paz was hailed by human rights groups. In Guatemala, like other Latin American countries who lived through periods of violence and human rights violations at the hands of the government, there were amnesty laws to protect those in power.
The first trial against Rios Montt represented the first time that a former head of state was tried for genocide by his own nation's judicial system.
The first trial was almost derailed several times. Lawyers for Rios Montt lodged more than 70 motions and appeals, many seeking to end the process on technical or procedural grounds.
In the end, the trial was completed and the guilty verdict came down. In a nation where the powerful and the political elite have historically been able to act with impunity, the moment was big.
Ten days later, however, a higher court annulled the conviction and ordered a retrial, a move critics considered politically motivated.
Some observers say they saw the invisible hand of the political elite at work when a court ordered Paz y Paz -- the attorney general who indicted Rios Montt -- to step down seven months before her term was to expire.
Shortly afterward, the judge who handed down the guilty verdict against Rios Montt, Yassmin Barrios, was suspended by the Guatemalan Bar Association for alleged ethics violations.
There's no conclusive evidence that the actions against Paz y Paz and Barrios are retaliation for their role in prosecuting Guatemala's one-time dictator, but the sentiment among many is that this is exactly what happened.
The first trial unearthed Guatemala's complicated relationship with its own history as both protesters and supporters rallied outside the courtroom last year.
Rios Montt came to power in a March 1982 coup, only to be overthrown 18 months later. During the trial, prosecutors argued that Rios Montt's junta government oversaw the bloodiest period of the country's 1960-1996 civil war that left more than 200,000 people dead and 1 million refugees, according to various truth commission reports.