Monica Arias Hernandez, daughter-in-law of slain Mexican activist Marisela Escobedo, has been granted political asylum by the United States, her family said in this Texas border city.

The 34-year-old Arias was a witness at the trial of the suspected killer of her sister-in-law, Rubi Marisol Freyre, and has become the third Mexican national granted asylum in El Paso, attorney Carlos Spector said.

An Internet campaign (www.mariselaescobedo.com) was launched on Tuesday to pressure the Mexican government into bringing those behind the killings of Escobedo and her daughter to justice.

The Web site offers evidence and videos from security cameras of Escobedo's slaying on Dec. 16, 2010, while picketing in front of the Governor's Palace in Chihuahua city, the capital of the like-named northern Mexican state.

The mere act of demanding justice for Rubi, who was 16 when she was killed in 2008, can endanger your life in Mexico, Arias told Efe.

Marisela Escobedo was gunned down after spending two years demanding justice for Rubi.

Escobedo had staged numerous marches and other protests in Ciudad Juarez, located across the Rio Grande from El Paso, and in Chihuahua city, demanding that the governor ensure there was justice in her daughter's case.

The 52-year-old woman staged her protest in front of the Governor's Palace after learning that Sergio Barraza Bocanegra, Rubi's boyfriend and the main suspect in her killing, had moved to Zacatecas state after being acquitted at his first trial and joined Los Zetas, perhaps the most ruthless of Mexico's powerful drug cartels.

"When they murdered my mother-in-law in front of the Governor's Palace in Chihuahua city without any authority doing anything to help her or to investigate her homicide, and later with the murder of Angel Valles, a witness in the trial against Barraza, I realized that I could be murdered at any time and nothing would prevent it," Arias said.

Arias, like Valles, was a witness at the trial of Barraza, who was released due to lack of evidence in the case.

She fled Mexico with her two children in March and sought refuge in El Paso, moving immediately to request political asylum.

"I felt totally defenseless. Over there (in Chihuahua), the authorities provide no support," the former financial executive said, adding that she was "more afraid of Mexican authorities than of the organized crime groups."

Escobedo's two sons, Alejandro, who is Monica's husband, and Juan Manuel, requested political asylum at a border crossing in December 2010.

Ricardo Escobedo, Marisela's brother and a witness to her killing, joined them in the asylum bid.

Videos recorded by security cameras around the Governor's Palace show a "suspicious and total absence of police," Juan Manuel Freyre said.

"At that place, since it's in front of the Governor's Palace, there were always patrols from the state, municipal and other police departments, and on that day, strangely, during the six minutes that went by from the time the killers spotted my mother until they fled after murdering her, there was not even one," he said.

The brother of Marisela Escobedo's boyfriend was kidnapped and murdered, and the family received death threats during the activist's funeral last December in Ciudad Juarez, Freyre said.

"We speeded up the funeral and from there my brother, Alejandro, my uncle, a daughter of Rubi's and I went to the Santa Fe international crossing (Paso del Norte in El Paso) and requested asylum on Dec. 18, 2010," Freyre, who plans to continue fighting for justice for his mother and sister, said.

Arias, for her part, said she would continue to support her brother-in-law and husband in their bid to get political asylum, but she planned to stay out of the campaign to get justice for Marisela and Rubi out of fear for her own safety.

The U.S. government had previously granted political asylum in El Paso to Cipriana Jurado, an activist from Ciudad Juarez, Mexico's murder capital, and journalist Alejandro Pacheco.

"The Mexican government is trying to silence those who bring this out and the United States recognizes this," Spector said.