Sister Barbara Ann Ford, a member of the New York-based Sisters of Charity order, was shot dead May 5 when two well-dressed men hijacked her pick-up truck in a busy section of Guatemala City. Sister Barbara's killers later abandoned the truck a few blocks away and stole another vehicle, which they then discarded a short distance away.

Police called to investigate quickly described the crime as an act of delinquency gone wrong. But human rights activists claimed the sequence of events fitted a pattern consistent with other politically motivated killings in recent years.

The Mutual Support Group, Guatemala's biggest rights organization, declared on May 7 that Sister Barbara's killing was "an extra-judicial execution … of a political nature."

Sister Barbara, a 62-year-old nurse, had helped prepare the church's landmark 1998 report—Guatemala, Never Again!—which blamed the nation's military for most of the deaths in the 36-year civil war that ended in 1996. More than 200,000 people, mostly indigenous Mayans, were killed or "disappeared"—abducted—during the conflict.

In a statement on May 11, the Guatemalan Catholic Bishops' Conference said the nun's death was symptomatic of an "anti-culture of death that undermines fundamental human dignity." The killing also demonstrated "the incapacity of the authorities in charge of security and the application of justice."

Responding to criticism, Interior Minister Byron Barrientos announced he was requesting assistance from the U.S. embassy here. A source in the Interior Ministry said agents from the Federal Bureau of Investigation would ...