ARGENTINA:Thousands of protesters have taken to the streets to mark the first anniversary of the disappearance of Jorge Julio Lopez, a key witness in the successful prosecution of a police chief from the "dirty war" years.
Many of those demonstrating on Tuesday hoisted banners bearing the rumpled likeness of Mr Lopez, who was 78 at the time he vanished. His name and face have become emblematic of civil society's determination to prosecute abusers from the former military dictatorship who left thousands dead or missing.
"We are convinced that the disappearance of Jorge Julio Lopez is a message to spread fear, to make us forget what happened," said Enrique Fukman, a former political prisoner and protest organiser.
Mr Lopez is believed to be Argentina's first and only political desaparecido (disappeared) since the restoration of democracy in 1983 after seven years of military dictatorship.
Argentina, under the leadership of left-leaning president Nestor Kirchner, has gone further than most Latin American nations in pursuing former officials of the military juntas of the 1970s and 1980s. Hundreds of ex-officers face trials after pardons and amnesties were revoked.
But the Lopez case underscored the vulnerability of witnesses, often former torture victims themselves, whose testimony is important to bringing suspects to justice.
"The protection of witnesses is a crucial factor that has been missing," said José Miguel Vivanco, executive director of the Americas division of Human Rights Watch.
"The perpetrators of these crimes have enjoyed full protection until now, so they are going to do everything in their power to obstruct investigations," Mr Vivanco said.
"I don't doubt that Julio Lopez was kidnapped for revenge and as a warning to others," Pino Solanas, a film director and opposition presidential candidate, told Pagina/12 newspaper. "Behind all this is the residual apparatus of the dictatorship."
The government says it has increased security for witnesses, providing escorts and other protection. But some still have reported threats. The spectre of retaliation hangs over the trials.
Authorities say they continue to investigate the case of Mr Lopez's disappearance. No remains have been found.
As a trade union activist, Mr Lopez was arrested during the dictatorship, and interrogated with electric shocks, according to his testimony. He eventually was released and returned to life as a construction worker and family man.
However, relatives said he was determined to seek justice. The chance came last year.
Mr Lopez provided crucial testimony in the trial of Miguel Etchecolatz, a notorious former provincial police chief accused of taking sadistic delight in the torture and murder of detainees.
Among other things, Mr Lopez linked Etchecolatz to the execution of a young activist couple shot while in custody at the lockup where Mr Lopez was being held.
The day after Mr Lopez disappeared, Etchecolatz was convicted of illegal abduction and homicide. He is serving a life sentence. - (LA Times-Washington Post service)