In a historic ruling that has been four decades in the making, a United Nations-backed tribunal known as the Extraordinary Chambers in the Courts of Cambodia found Khmer Rouge leaders Nuon Chea, 92, and Khieu Samphan, 87, guilty of genocide today, according to the New York Times.

In addition to the crime of genocide, each were declared guilty of murder, extermination, deportation, enslavement, imprisonment, torture, persecution on political, religious and racial grounds, and other inhumane acts.

The ruling marks the first formal declaration of genocide during the Khmer Rouge rule and added another life sentence to each of the criminals’ sentence following the life sentences they received for crimes against humanity in a ruling from the Chambers in 2006.

“It’s a positive development that, for better or worse, is far overdue,” said Long Beach resident and Cambodian-American Laura Som. “The journey to find justice can be long and, at times, very trying as victims carry our losses and become re-traumatized because the light at the end of the tunnel seems to get dimmer at times. The process of standing up and perseverance with our demands for justice is how we honor those whom we have lost, ourselves and for humanity.”

The militant Khmer Rouge ruled over Cambodia from 1975 to 1979 when the regime was able to overthrow the then-U.S.-backed government when the U.S. left neighboring Vietnam. That led to the murder of millions of Cambodians, with estimates claiming the loss of anywhere between 1.7 and 2.4 million Cambodians due to execution, labor exhaustion, or starvation (of the 3.3 million deaths that occurred during the time of civil unrest).

The Khmer Rouge—through the push of fundamental communism—nearly annihilated the Cambodian population via the systematic killing of hundreds of thousands of its so-called enemies. To make sure not too many questioned the Khmer Rouge, the regime would use film propaganda to show the country how “great” things were with their “great” Democratic Kampuchea. This propaganda is the only documentation left of the era—and what is missing, of course, is the story behind those pictures, as noted in the Academy Award-nominated film “The Missing Pictureby” Rithy Pahn.

Long Beach boasts the largest Cambodian population anywhere outside of Cambodia itself. Many of the Cambodians here are immigrants, and it is not uncommon to hear stories of struggle and pasts engulfed in violence, as many witnessed the disastrous results of the Khmer Rouge.

The Chambers trial started in 2003 and has since faced immense trouble, with its second judge leaving the trial in March of 2016 after feeling that the Cambodian-led side was preventing further investigation into the crime—the second such accusation by an outside judge.

It has since been largely criticized for its glacial pace: Before Friday’s conviction, the Chambers had only handed out three sentences and went through a revolving door of judges. Two of those were Chea and Samphan’s first life sentences in 2014 while the third was another life sentence in 2010 for Kaing Guek Eav, known as “Duch,” for war crimes, crimes against humanity, murder and torture. Duch was the head commander of the Tuol Sleng S-21, a school that was converted into a prison in Phnom Penh, and the place where more than 14,000 people died under his watch.

To add to the criticism, the cost of the trial currently stands at over $300 million, according to CNN, while Chea, known as “Brother #2” and Khmer Rouge leader Pol Pot’s brother-in-law, and Samphan, known as “Brother #4,” are reaching the end of their natural life.