The son of rights activist Marisela Escobedo, who was shot and killed in northern Mexico in 2010 while demanding justice for the murder of her daughter, said a suspect arrested in his mother's slaying is a "scapegoat."

Juan Frayre Escobedo, who fled to the U.S. city of El Paso after receiving death threats, said in a press conference Wednesday that the "real killer" is a U.S. citizen.

"My mother's brother was a witness to the murder and denounced him to the Attorney General's Office. We know he's an American," the activist's son said, although he did not reveal the identity of the purported killer and only added that he may be living in the Mexican border city of Ciudad Juarez or in El Paso, Texas.

Referring to Jose Enrique Jimenez Zavala, who was presented last weekend by Chihuahua state authorities as Escobedo's suspected murderer, Frayre said he is a "scapegoat" and that he "may have been pressured into confessing to something that isn't true and solve the case."

According to state authorities, the 29-year-old Jimenez Zavala headed an arm of the Los Aztecas criminal gang and also is suspected of involvement in the massacre of 16 people in April at a bar in Chihauhua city, capital of the like-named state.

The suspect was arrested on Oct. 4 in a shopping center parking lot in that same city, where Escobedo was murdered.

Prosecutors said earlier this month that Jimenez confessed that he killed Escobedo as part of a deal between drug gangs.

The suspect also told investigators that Sergio Barraza, the suspected killer of Escobedo's 16-year-old daughter, Rubi Marisol Frayre, was working for Los Zetas in Zacatecas state and the activist's protests were garnering too much press coverage.

Jimenez said he received the order to kill Escobedo from Jesus Antonio Rincon Chavero, a former police officer who is the No. 3 man in the La Linea gang, the Chihuahua state Attorney General's office said.

Rincon Chavero, who is serving time in federal prison, said the order came from "much higher," Jimenez told investigators.

Rubi Marisol Fraire was killed in 2008 in Ciudad Juarez. Escobedo accused Barranza, Rubi's then-boyfriend, of the crime and embarked on a crusade for justice.

Barraza was arrested and taken to Ciudad Juarez and allegedly confessed to the crime there, but he was acquitted in a 2010 trial due to a lack of evidence.

An appellate court subsequently overturned that decision and found Barraza guilty, but he remains at large.

Incensed at seeing her daughter's killer go unpunished, Escobedo led marches and protests to demand justice until she was gunned down on Dec. 16, 2010, while picketing in front of government offices in the Chihuahua state capital. EFE