Activist who identified daughter's attackers was killed on Mexican Mother's Day

Relatives of the 43 students missing from Ayotzinapa take part in a demonstration in Mexico City, on Feb. 22, 2016. (Reuters)

The governor of the Mexican state of Tamaulipas said he will not allow the death of human rights activist Miriam Rodriguez to become just another statistic in the 10-year deadly drug war.

Rodriguez was killed Wednesday night while at her home in the town of San Fernando, where she was widely known for her efforts helping locate some of the 5,500 people currently missing in the state.

San Fernando is about 90 miles south of Brownsville, Texas, and is a critical point on drug- and migrant-smuggling routes to the border.

EX-GOVERNOR OF TAMAULIPA'S LONG FLIGHT FROM JUSTICE ENDS

Rodriguez was living in the U.S. when her daughter went missing in 2012. She returned to look for her and did not stop until she found her remains two years later in an unmarked grave. By then she had become a widely known human rights activist and eventually founded the group Citizen Community in Search of the Disappeared.

According to people who knew her, Rodriguez had received numerous death threats and feared for her life because she had identified her daughter’s attackers — alleged members of the Zetas cartel.

"They are going to kill me one day. Of that not I have doubts," she told an acquaintance interviewed by El Universal.

Tamaulipas Attorney General Irving Barrios said the state had been protecting Rodriguez, sending police patrols three times a day to her house. Barrios also said nine people had been put on trial for her daughter's kidnapping and murder.

TEXAS MOTHER AND DAUGHTERS AMONG THOSE KILLED IN MEXICAN FAMILY MASSACRE

A number of organizations, including the Office of the United Nations High Commissioner for Human Rights in Mexico, called on the authorities to ensure that this murder does not go unpunished.

"Beyond her murder, it is imperative to address the structural factors that have placed the families of missing persons in a serious situation of vulnerability," said in a statement the office in Mexico of the United Nations High Commissioner for Human Rights.

Rodríguez, 50, was killed on the day Mexico celebrates Mother's Day, which the UN noted gives the murder “a chilling symbolism.”

The AP contributed to this report.