A US court has begun hearing evidence against a man accused of conspiring to murder the archbishop of El Salvador 24 years ago.
Oscar Arnulfo Romero, a champion of the poor and critic of military rule, was killed as he held mass.
His death, which caused international outcry, has gone unpunished mainly because of a Salvadoran amnesty law.
A US human rights group is bringing a civil action against a retired Salvadoran army officer.
Alvaro Rafael Saravia is said to be a close associate of the man who masterminded the 1980 killing and is accused of providing money and logistical help to the archbishop's assassin on the day of the crime.
The former officer has lived in the US for the past 20 years, but has not been seen in public since the civil lawsuit was filed against him last September. The hearing will be held in his absence.
Under US federal law, US courts are allowed to try foreigners charged with summary killings, even if committed outside the US, as long as the defendants have registered addresses inside America.
The lawsuit in Fresno, California, has been brought by the San Francisco-based Centre for Justice and Accountability on behalf of one of Romero's relatives and seeks compensation for the archbishop's death.
The group says it will introduce new evidence including testimony from an as-yet-unidentified witness who will attest to Mr Saravia's involvement in the killing.
A truth commission set up by the United Nations in the 1990s concluded that the plot to kill Archbishop Romero was led by the former army major, Roberto d'Aubuisson.
Mr d'Aubuisson, who died in 1992, was accused of running right-wing death squads in El Salvador during that country's civil war in the 1980s.
Terry Lynn Karl, a professor of Latin American studies and
political science at Stanford University, said the murder
was politically the most significant killing in El
"If you kill an archbishop, you can kill anybody," Mr Karl
told the Associated Press.
"It was a signal to hardliners that all constraints
were off. It launched El Salvador into the most intense
repression in its history and into civil war."