Mexican authorities have arrested the alleged murderer of a Catholic priest and prominent human rights defender whose killing triggered international condemnation, officials announced Tuesday.

Father Marcelo Perez, 51, was shot dead on Sunday in the southern state of Chiapas, which has been shaken by escalating gang-related violence.

The Chiapas public prosecutor’s office identified the alleged “material author” of the crime as Edgar “N,” in line with the usual practice of not giving full names.

It said it had used security camera footage, witness testimony and other leads to identify the suspect.

Perez’s work on human rights had been recognized by international organizations.

The Mexican office of the U.N. High Commissioner for Human Rights denounced the Indigenous priest’s murder and called for an “exhaustive” investigation.

Rodrigo Aguilar Martinez, bishop of the southern city of San Cristobal de las Casas, called for “decisive action to restore peace in the country and especially in Chiapas.”

The state prosecutors’ office said Rev. Pérez was shot dead by two gunmen when he was in his van, just after he had finished celebrating Mass.

“Father Marcelo was leaving the … parish after officiating mass and was heading to Guadalupe Church, when two people aboard a motorcycle opened fire,” the office said.

He had received threats after speaking out against drug trafficking and related violence in Chiapas, which has been gripped by a cartel turf war.

Hundreds of mourners attended a funeral for Perez in his hometown on Tuesday, chanting “Long live Father Marcelo, priest of the poor!”

Mexico has seen more than 450,000 murders since a controversial military anti-drug operation was launched in 2006, according to official figures.

In 2022, two Jesuit priests were killed inside a church in a remote mountain community in northern Mexico. In 2016, three priests were killed in just one week in Mexico.