“It’s not oriented towards defining guilt or innocence; it’s about finding a solution,” he said.

Ryan says that the system will work by giving those who participated in the genocide the opportunity to admit their actions.

“It’s only going to work if people are truthful,” he said. Suspects will have to “come to the lead and say, ‘Yes, I took part. But I was young, I was scared, I was under the influence of a teacher.’ Those who insist on their innocence will have to wait for a trial.”

Many are in favor of the gacaca system, hoping it will deliver more lenient sentences. Judges may hand down a maximum sentence of life in prison, but may not issue the death penalty.

At the gacaca hearings, suspects have no lawyer, and the judges—ordinary citizens elected by the community—will have received scant legal training. These shortcomings created considerable controversy, which delayed their implementation until now, eight years after the massacres.

But Ryan believes that the promotion to attorney general of Gerald Gahima, his co-author for the memo, is what definitively led to its transformation into law.

Gahima was from the start opposed to the other major proposed solution—importing judges and lawyers from abroad.

“He said, ‘We’re not going to rent justice,’” Ryan said.

However otherwise flawed, the gacaca system is completely indigenous. It also has the advantage of great speed—all of the trials may only take five years, by optimistic estimates.

The process will apply only to civilians who partook in the terror. The masterminds will be tried in a U.N.-sponsored International Criminal Tribunal in neighboring Tanzania.

Ryan acknowledges that the solution is not perfect—but says no attempt to punish war crimes can be.

“There is never a situation in which you can put every war criminal in jail,” he said.

Ryan had extensive background in the war crimes field: From 1980 to 1983 he was the Director of the Office of Special Investigation for the U.S. Department of Justice, serving as the chief Nazi war crimes prosecutor for the United States—the first person to hold the position.

His scholarship has focused on understanding what is at the origin of all mass slaughters.

“The Holocaust, Cambodia and Rwanda have all caused us to rethink the laws of war,” Ryan said. “My whole course is about trying to get beyond their very obvious dissimilarities.”

In this way, he hopes the gacaca solution will have resonance with other war-ravaged countries.

“The point is to look at other definitions of justice,” Ryan said. “This is one of those ways. Would this work with al-Quaeda terrorists? No—But it may teach us something that will apply in East Timor or Chechnya.”

This summer, his students may feel more encouraged to hope that their study of the laws of war can make a difference.

“Every year, I pass out that memo, as what I would suggest for Rwanda,” Ryan said. “Now I can say, that’s what they are actually doing.”

—Staff writer Eugenia B. Schraa can be reached at schraa@fas.harvard.edu.