Catholics in Kenya commemorated the life of American missionary John Anthony Kaiser, a Catholic priest and human rights defender. He was particularly vocal in condemning politically motivated tribal clashes during the 1990s and whose assassination in the year 2000 shocked the country.

Kaiser, who was 67, is best remembered for having served among the poor while advocating for justice for the oppressed and respect for human rights.

Twenty-three years later, the actual motive of Kaiser’s murder remains unsolved, and his killers remain at large.

READ: Kenyans Mark 25th Anniversary Of Al-Qaida Bombing Of US Embassy

On the morning of Aug. 24, 2000, his body was found near the town of Naivasha, located about 50 miles northwest of the capital, Nairobi, along the highway linking the capital to Nakuru in Kenya’s rift valley. His body was found lying next to a shotgun with a wound to the back of his head.

Last month, a commemorative Mass was held at the scene of the murder in Morendat with the theme “Let Justice be Our Shield and Defender.”

“We are gathered here where his body was found, but we are not yet tired of asking who committed the murder," said the Rev. Cleophas Oseso, bishop of the Catholic Diocese of Nakuru.

Born on Nov. 23, 1932 in Perham, Minnesota, Kaiser was ordained a Catholic priest at St. Louis for the Mill Hill Fathers in 1964 and commissioned to Kenya, where he served for nearly three decades until his death. At the time of his death, he was stationed at Lolgorian Parish in Ngong Diocese.

“His murderers have not been found to date. This is a major concern,” said Bishop John Oballa, who heads the Diocese of Ngong.

Oballa noted that many people had been killed in the country for reasons tied to their zeal for human rights and dignity. He said the church would continue pressing for human rights and justice.

He called the late priest a man who stood for justice, defending the oppressed, those who were threatened, those who were evicted from their lands and those whose rights had been denied.

“And so today is not just to have that emotional memory of his departure but also to live and revive the memory of what he stood for,” said Oballa.

Following a request by Catholic bishops in Kenya, the national government opened an inquest into the priest’s death, which ended on June 12, 2007, after the investigation heard from 111 witnesses. The court found on Aug. 1, 2007 that Kaiser had been murdered, ruling out the “suicide theory” that had been floated by the Kenyan government and FBI. The presiding magistrate said she could not determine with certainty who Kaiser’s killers were on the basis of evidence tabled before her in the inquest.

Kaiser had risen to national prominence after he linked prominent leaders in the tribal clashes that rocked the East African country in the 1990s, including then-President Daniel Arap Moi. Kaiser also wrote several letters calling on government officials to look into the welfare of internally displaced people who were housed in camps.

In 1993, when Kenya was rocked with ethnic violence and land clashes in parts of the country, Kaiser offered to work at a camp for internally displaced persons in the Maela region.

“He was spontaneous and a down-to-earth priest who was equally full of kindness and embraced all regardless of their status in society. He thrived in empowering the poor and speaking out for the oppressed, especially the homeless,” Kenya's Catholic Church Department for Justice and Peace Agenda said of the slain prelate.

A plaque was put up in his memory at the scene. It has since been removed to pave way for the upcoming expansion of the highway.

Oballa said since the plaque “was constructed on a spot that would interfere with the expansion of the road, in conjunction with the (road construction authorities), we negotiated and found another place where this monument can be erected.”

Joseph Maina is a Kenyan journalist. He holds a Bachelor of Arts degree in journalism and media studies from the University of Nairobi. For the past decade, he has served as a correspondent for various print and digital publications in his native Kenya, Rwanda and South Africa.

This story originally appeared at Religion Unplugged and is republished here with permission.