Arrested U.S. Woman Casts a Long Shadow : El Salvador: Arms case could be a pivotal event in the history of U.S. relations with the war-torn country.

A few months after moving to El Salvador nearly five years ago, 23-year-old Jennifer Jean Casolo wrote to a close friend in the United States, describing her feelings and motivations.

“I question the value of traditional success and security when the vast majority of beings on this Earth rarely think beyond food for their children and will never know security,” she wrote.

She described meeting a young Salvadoran whose father had died in the nation’s seemingly endless fighting and whose brother was in exile. “I felt like I wanted to cry,” she wrote. “But I also feel challenged to live without fear.”

By all accounts, Casolo, now 28, met that challenge. From a poorly financed office in San Salvador, she traveled the often dangerous country, arranging visits for thousands of Americans. Most were church workers, but they included congressional aides and other U.S. VIPs who over the last several years have flocked to El Salvador to see firsthand the devastation of civil war and to judge for themselves the validity of U.S. support for the nation’s government in its fight against Marxist guerrillas.

In that role, Casolo became one of the best-known Americans without official status in the country, as she provided a center for the church movement that members of the Salvadoran military and the nation’s governing party have long suspected of aiding the guerrillas.

But with violence in the country and threats against church workers escalating, Casolo’s will to continue had begun to flag. She wrote friends about the stress she was under and had told her mother she was planning to return home this week.

Shortly before midnight Saturday, her plans changed abruptly. Police raided the white stucco house she had rented in the capital for the last couple of months, digging up a large cache of arms--including more than 20,000 rounds of ammunition, grenades and explosives--buried in the back yard.

The building, Salvadoran government officials say, was a guerrilla safehouse. And Casolo, now under arrest along with two Salvadorans who reportedly used the house occasionally, faces charges of collaboration with the rebels.

In the United States, Justice Department prosecutors and FBI officials met Monday to consider charging her under the seldom-used Neutrality Act, which bars American citizens from taking sides in other nations’ wars.

The case may be a pivotal event in the history of U.S. relations with El Salvador. If Casolo is guilty, her wide contacts with virtually every church-related organization in the country would provide the government a reason to expel all American church workers--something that conservatives in the military and the ruling party, the Nationalist Republican Alliance, have long sought.

On the other hand, if, as Casolo’s friends insist, she has been framed by a government determined to rid itself of foreign church workers, the move against Casolo could severely damage the Salvadoran regime’s chances of continued U.S. aid.

Monday night, Casolo’s supporters said that former U.S. Atty. Gen. Ramsey Clark plans to travel to San Salvador with several supporters of Casolo’s to seek the young woman’s release.

At the center of the swirling charges stands a slightly built, energetic young woman, barely 5 feet tall, animated, like many Americans who have traveled to El Salvador in recent years, by a deeply felt religious faith.

“Here I am in El Salvador,” she told her friend in the first of a series of letters she wrote after arriving in the country. “I have no pretensions of doing something important; at least I will do my best not to hurt any person.

“I don’t view myself as part of a movement,” she wrote. “I don’t adhere to an ideology; my actions come from experience, from a feeling of caring about the poor.

“The most valuable work I can do is to educate the North American public about the questions that are pertinent here and hope they come up with answers and actions that will bring peace with justice to El Salvador.”

Casolo grew up poor in Thomaston, a town of 6,000 located in an aging industrial valley of northwestern Connecticut. Her divorced mother worked for one of the state’s big insurance companies. In a high school class of barely 70 students, she was president of the student council, chief of the honor society, chairwoman of the Spanish Club and head cheerleader.

A full scholarship brought Casolo to Brandeis, a prestigious private university located outside Boston. Four years later, having graduated with highest honors, Casolo turned aside suggestions that she apply to graduate school to pursue a doctorate in American literature. Instead, she took a post with the Brethren Volunteers, the social-action arm of the Illinois-based Church of the Brethren, a long-established pacifist church.

Casolo worked initially on disaster relief projects, then moved to Seattle to serve as a social worker for Salvadorans being aided by a church-based “sanctuary” project that helped people fleeing the country avoid deportation from the United States.

“She demonstrated over two years with us a profound religious commitment,” said Donovan Cook, pastor of University Baptist Church in Seattle, which sponsored the project. “She was also a tremendous organizer. She was very adept at working on events that would be of educational importance.”

That organizational ability, coupled with Casolo’s interest in Latin America and fluent Spanish, caused Cook to recommend Casolo as the Salvadoran liaison for a new organization being set up in 1985, the Christian Education Seminars.

The idea worried Casolo’s family, her mother recalled Monday. “We thought she might be caught in a cross-fire,” Audrey Casolo said.

But the post appealed to Jennifer Casolo’s increasing desire to put her religious beliefs about sharing her lot with the poor into action.

The San Antonio-based group operates with an annual budget of about $100,000, most of it contributed by individuals who have participated in its travel seminars, according to a spokesman for the organization. It was established to organize tours of El Salvador for members of U.S. churches. Its national board includes a number of prominent American church leaders, headed by the Rev. Daniel Long of San Antonio, who directs Hispanic ministries in Texas and Louisiana for the Evangelical Lutheran Church in America, one of the country’s largest denominations.

“The focus of our work is the church,” the spokesman said. “Basically, the idea is to allow spokespersons of different groups to get a perspective on the situation in El Salvador.”

The job was one that brought Casolo into contact with most of the centers of power in Salvadoran society--the military, the government, the churches, the U.S. Embassy.

“She was kind of like a tornado going around making connections,” recalled John Rivera, a former Carmelite brother who visited El Salvador on one of Casolo’s delegations in 1985.

“I respected her, I liked her,” said one of those connections, a senior officer of the Salvadoran army who spoke to several of the delegations that Casolo brought to the country.

Now, however, “For me she has betrayed us. We showed her that we have nothing to hide. . . . We helped her in her work, and now I think she probably told the guerrillas I am like this and like that. To think that she played a role in their logistical network. . . . “

Friends of Casolo’s, of course, deny she did any such thing.

“I don’t know if she’s being framed or not,” Audrey Casolo said, but “I feel she had no knowledge of what was in the yard.”

Others talked of the young woman’s longtime expression of pacifist beliefs and her complaints to visitors about the violence of both the government and its guerrilla opponents.

Friends talk, as well, about the stress of Casolo’s job and the toll that the escalating violence in El Salvador had begun to take on her.

Late last year, Casolo wrote to her American correspondent that she had had a run-in with police officials--an encounter she described as a misunderstanding.

“I am still under investigation, and while I know that all my activities have been completely legal, I fear the lack of real application of the law here,” she wrote. “A grudge can go a long way.”

This story was reported by Times staff writers Richard Boudreaux, Marjorie Miller, and Tracy Wilkinson in El Salvador and by John Dart in Los Angeles, David Treadwell in New York and David Lauter in Washington. It was written by Lauter.