MEXICO CITY — On the eve of Mexico's Day of the Dead this year, authorities in Veracruz declared triumphantly that they had solved one of the decade's most notorious slayings of a journalist in Mexico.

They trotted before reporters a sad-sack figure, one Jorge Antonio Hernandez Silva. They proclaimed him guilty of the April slaying of Regina Martinez, a highly respected reporter for the national Proceso magazine. He had confessed, the Veracruz government said, and the motive was robbery.

Case closed, they said with an almost palpable sigh of relief. The coastal Veracruz state had become the most deadly place for journalists in a country considered one of the deadliest places in the world for journalists. And Veracruz authorities were coming under enormous pressure to do something about the killings and disappearances, which were giving the state a bad reputation and hurting tourism.

Someone forgot to tell Hernandez Silva to play along. Hours after he was presented to reporters, he appeared in court at the local equivalent of an arraignment. There he blurted out that he had been tortured by state officials bent on extracting a confession. They forced water up his nose and threatened to kill his mother. He had nothing to do with Martinez's slaying, he declared.

That Hernandez Silva had allegedly been tortured should come as little surprise to observers of the violent battle against drug cartels that has gripped Mexico for the last six years. Under the government of President Felipe Calderon, whose six-year term ended Dec. 1, the use of torture by state security forces soared to unprecedented levels, according to several Mexican and international human rights organizations, as well as testimony collected by The Times.

Various forms of torture, including the "waterboarding" familiar to Americans after Sept. 11, sexual assault and electrical shocks to genitals, have been inflicted by state security agencies on Mexicans detained on sometimes specious suspicion.

The technique described by Hernandez Silva is an old one in Mexico, known in slang as the tehuacan, for the brand of carbonated water often forced up the victim's nose (spiked, sometimes, with chili powder).

Human rights organizations are especially critical of the Calderon administration for failing to stop or investigate what they term "systematic" torture, long after the practice was exposed.

One group, the New York-based Human Rights Watch, this year forwarded a report on torture and other abuses to prosecutors at the International Criminal Court, or ICC, at The Hague, as the tribunal considers whether to open an investigation into Calderon on possible crimes against humanity. Although it is unlikely that the court would prosecute a former head of state from a country that has functioning institutions, the case would nevertheless embarrass Calderon and put pressure on his successor, President Enrique Peña Nieto, to change course.

Calderon's war on drug cartels eliminated a number of notorious traffickers but chalked up an abysmal human rights record. The number of complaints multiplied in comparison with previous administrations. In addition to torture, state security forces were accused of "extrajudicial" killings of detainees and "enforced disappearances," when military or police kidnap and "disappear" suspects.

Most of the abuses, which also included mock executions, occurred in the first hours or days of the victims' detention, before they were turned over to civilian judicial authorities and while they were being held incommunicado.

The Times reported in January 2012 that the Calderon administration deliberately concealed drug-war statistics, including the number of people killed, and, more recently, the number of Mexicans reported missing. A list of about 20,000 people who have disappeared in the last six years has been leaked to The Times and other news organizations but never published by the government.

In a report released late last year, and forwarded this year to the ICC, Human Rights Watch documented 170 cases of torture by all Mexican security forces — the army and navy and federal, state and local police — in five Mexican states. The organization submitted the report to Calderon and members of the Mexican Congress in November 2011. It also documented 39 cases of "enforced disappearances" and 24 cases of killings by state security forces.

Since then, Human Rights Watch says, only superficial investigations were opened and virtually no one punished.

"In fact, several years after many of the abuses … were committed and formal investigations were opened, not a single official has been sentenced for the crimes, contributing to an ongoing climate of impunity," the organization said in a letter to the ICC, made available to The Times. "These are not isolated acts. Rather … these abusive tactics are endemic to Mexico's counternarcotics efforts."

The Defense Ministry has paid out about $1.7 million in reparations to 85 Mexican families whose members have suffered illegal death or torture at military hands, the newspaper Milenio reported recently, citing information obtained through Mexico's equivalent of the Freedom of Information Act.

When Hernandez Silva denounced his alleged torture in court, no reporters were there to cover it. Reporters in Veracruz, notoriously intimidated by both state government officials and by hard-charging narco-traffickers, rarely write about anything that challenges the official line. The account in this article comes from a federal official monitoring the case, who was not authorized to discuss it publicly.

Veracruz authorities have not commented on Hernandez Silva's recanting of his confession. The purported confession by Hernandez Silva, who is said to be 34 and illiterate, was rendered even more dubious by the fact that it did not match details of the crime scene, such as where in her home and how Martinez was killed, according to people with access to investigative reports.

A reporter who often covered government corruption, Martinez was beaten and strangled to death. Few of her possessions were missing.

Hernandez Silva, at last report, was found guilty by the judge and ordered to be detained. He faces a 30-year sentence.

wilkinson@latimes.com