Family, friends and strangers moved by the death of District resident Rodrigo Rojas 11 days ago in Chile attended a protest rally and memorial service here last night, vowing to seek vindication for his death.

About 300 people, many carrying signs denouncing the government of Chilean leader Gen. Augusto Pinochet and U.S. complicity in his 13-year-old regime, marched up 16th Street for a mass at the Shrine of the Sacred Heart.

On the steps of the church, Rojas' mother, Veronica de Negri, and her younger son, Pablo, held up photographs of Rojas and joined in the chants of "We want justice."

"We want justice for Rodrigo and all the Rodrigos who have been murdered by Pinochet," said Marucha Harrigan, a family friend. "We cannot remain silent. We cannot accept the loss of one more life."

Rojas, 19, died in Santiago of severe burns on July 6. He had gone to Chile -- from which his mother had fled in 1975 -- to learn about his native land and its people. Human rights workers have said that he and a young Chilean woman were beaten, doused with gasoline, set afire and abandoned in a ditch by members of the Chilean army.

The allegations have been denied by military officials.

Veronica de Negri said that she had received no new information about her son's death since she returned from his funeral in Chile last week. "How can any human being watch another burn in a pit? I just don't understand," she said. "The only one who can give an explanation is the government of Chile."

Although the Pinochet goverment has appointed a special prosecutor to the case, Rojas' friends and family said yesterday that they are not hopeful that anyone will be brought to trial.

Harrigan said the family was trying to raise money for an independent investigation.

"In 13 years there hasn't been a military man brought to justice," said Marcelo Montecino, who eulogized Rojas at the mass. "I have no faith in the Chilean judicial system."

In the United States, Rojas' death has drawn quick and pointed criticism from congressional leaders.

Yesterday, 20 senators sent a letter of protest to the Chilean minister of the interior, and Rep. Mervyn Dymally (D-Calif.) introduced a resolution condemning the slaying.

Some political leaders expressed their concern personally by attending last night's mass. Sens. Tom Harkin (D-Iowa) and Edward Kennedy (D-Mass.) read passages from the Bible, as did the Rev. Jesse Jackson.

District Del. Walter Fauntroy (D) also attended.

Father Brian Hare of the National Association of Catholic Bishops urged the mourners to use Rojas' death as a symbol for fighting injustice in Chile and in other foreign countries.

His plea was reemphasized throughout the service with the playing of Chilean songs of protest as well as with Catholic hymns.

"We are not spectators," Hare said. "What is done here, what is decided here, makes a diffence," he said.