MEXICO CITY — Usually, human rights activists and victims are on the same side of a conflict. But the case of Israel Arzate has put the two allies in opposite camps in Mexico, a reflection of how the absence of justice distorts reality in this violent country.

Arzate, 28, was one of a small handful of people formally accused by authorities of perpetrating one of the most notorious massacres in recent Mexican history. Fifteen mostly young people were shot to death as they celebrated a soccer victory in the border city of Ciudad Juarez in January 2010.

It was a milestone massacre because it forced then-President Felipe Calderon, who initially dismissed the incident as a fight among drug traffickers, to acknowledge the killing of innocents and to focus attention and money on Ciudad Juarez, at the time one of the deadliest cities in the hemisphere.

But, according to Arzate and a legion of human rights organizations who rose to his defense, the young street vendor of CDs was picked up by the military arbitrarily and tortured into making a false confession.

Last week, the Mexican Supreme Court seemed to concur and ordered his release. The court stated that he should not have been arrested by the military but by civilian police, a decision hailed by Amnesty International, Human Rights Watch and numerous Mexican groups.

But the mothers of the dead youths were livid. For them, Arzate's conviction had come to represent one of the only shreds of justice they had to this point.

Arzate, in an interview Sunday, said he feels for them but that their anger toward him is misdirected. "If they could see the details of the case, they would have a different viewpoint," he said.

In 2010, authorities were desperate to charge a culprit in the massacre in the Villas de Salvarcar neighborhood precisely because it had received so much attention, and because families were especially vocal in demanding justice. In a remarkable moment, one mother verbally attacked Calderon, telling him at a town hall meeting that he was not welcome in Ciudad Juarez and that he had to beg forgiveness of the survivors — which he did.

Arzate contends that he was a convenient scapegoat. He had had a run-in with the law a short time earlier over problems with his truck, and then, he said, suddenly found himself arrested in the massacre.

"They grabbed me and pulled my sweater over my head," he said Sunday. Over the next four days, he said, they subjected him to electrical shocks, beat him, choked him and threatened to rape his wife.

"The government needed to relieve the pressure, and because they couldn't get the real culprits, they grabbed whomever they could," he said.

Although Arzate's release was hailed universally by human rights organizations, the state attorney general in Chihuahua, where Ciudad Juarez is located, said he would refile charges, essentially defying the highest court in the land.

And the mothers too remain adamant.

"There is not the least bit of doubt" that Arzate is guilty, Maria Guadalupe Davila, whose son was killed in the incident, told a radio interviewer. "What message does it send to the survivors, to those of us who managed to escape that terrible night, what message of justice?"

For human rights organizations, however, the Supreme Court decision was a landmark ruling that finally affirmed that confessions obtained through torture are not valid.

It has long been a tradition in the Mexican judicial system that suspects are tortured or pressured into making dubious statements of guilt.

"The Supreme Court's ruling is a long-overdue acknowledgment by the government that Israel Arzate's confession was obtained in violation of his rights and should never have been allowed as evidence," Jose Miguel Vivanco, head of the Americas department for Human Rights Watch, said in a statement. The group said it had documented 170 similar cases of torture.

"Beyond freeing Israel, the court should use the ruling to affirm a clear and unequivocal prohibition on the use of torture-tainted evidence in Mexico's justice system," Vivanco said.

One of the leading human rights organizations in Mexico, the Miguel Agustin Pro Juarez Human Rights Center, said it had "total respect" for the families of the Villas de Salvarcar victims but that the blame at this point lay with Chihuahua authorities who have "played" with survivors' feelings and failed to pursue real justice.

wilkinson@latimes.com