In Blow to Conspiracy Case, Mexican Suspect Released : Latin America: Judge finds crowd-control worker innocent in death of presidential candidate Colosio.

The government’s contention that ruling party presidential candidate Luis Donaldo Colosio was killed as part of a conspiracy suffered a serious blow Friday after a federal judge found a key suspect innocent.

Tranquilino Sanchez was released after more than a year in a maximum-security prison near the capital after a judge ruled that he had played no role in the March 23, 1994, killing.

Sanchez’s exoneration signals the crumbling of a conspiracy theory that has kept three men imprisoned, awaiting trial, for more than a year.

The government’s failure to prove a conspiracy could become a serious political problem because Mexicans have roundly rejected any hint that Colosio was killed by a lone gunman.

Polls show that most Mexicans are sure that the candidate was the victim of a plot reaching into the highest levels of the ruling political party.

Sanchez, now 60, was a member of the crowd-control team hired to protect Colosio during a campaign stop in Tijuana.

Sanchez and two other security guards--Vicente Mayoral and his son, Rodolfo--were arrested within days of the candidate’s murder, which followed a rally in the working-class Tijuana neighborhood of Lomas Taurinas.

A judge found that the case against another suspect, Rodolfo Rivapalacio, who organized the security team, was too flimsy to justify holding him for trial.

Nevertheless, Sanchez and the Mayorals have remained jailed as a series of special prosecutors discarded, then revived, conspiracy theories about Colosio’s death.

The government’s case against them was based largely on videotapes that allegedly showed them pushing through the crowd, supposedly to allow the confessed triggerman, Mario Aburto Martinez, to get close enough to shoot the candidate in the head.

The judge’s decision to free Sanchez makes it appear unlikely that the Mayorals will be convicted because the case against the three men was based largely on the same evidence.

No firm connection among the Mayorals, Sanchez and Aburto was ever proven. Aburto, who is now serving a 45-year sentence for the murder, has insisted that he acted alone.

However, authorities recently arrested another suspect, Othon Cortes, accusing him of firing a second gun that wounded Colosio in the abdomen as Aburto shot him in the head. The government had previously argued that Aburto fired both shots.

Cortes, like Sanchez, was part of the crowd-control team and active in the local branch of the ruling Institutional Revolutionary Party, or PRI.

As national chairman of the PRI, Colosio had recognized the first opposition victory in a state governor’s race in Baja California, and he was believed to have created enemies in Tijuana for that reason.

Many Mexicans believe that Colosio was murdered because hard-line elements of the PRI feared his reformist ideas.

In interviews after his release, Sanchez expressed no bitterness about his long imprisonment.

“I was treated very well, and I cannot complain,” he said.

He also insisted that, rather than aiding Aburto, he had tried to prevent the crowd from crushing Colosio as he moved toward a waiting motorcade.

“My conscience is clean. Before God, I feel clean. I don’t believe any conspiracy exists because, of course, I don’t know any of them,” he said, referring to the accused.

Prosecutor Daniel Aguirre Luna said he plans to appeal.