Twelve District residents were indicted yesterday on charges of felony murder, kidnaping and armed robbery in last fall's beating death of Catherine L. Fuller.

Fuller, 49, was attacked just before dusk last October as she walking home near Eighth and H Streets NE. Her slaying has been called one of the most brutal in Washington's history, and one in which the largest number of people ever have been indicted in a single homicide here.

Charges against three other people arrested in the case have been dismissed, law enforcement officials said yesterday. A source familiar with the case said that one defendant, not one of the 12 people indicted yesterday, has pleaded guilty to charges in Fuller's death. The source would not reveal the defendant's name nor to what charges the individual has pleaded.

The defendant's court file, the source said, has been sealed to protect the individual from possible recrimination from other defendants.

At least two other people who were arrested and charged in the case have not been indicted nor have their cases been dismissed.

According to court affidavits and law enforcement sources, Fuller was walking home with a bag of groceries when she was spotted by a group standing in a nearby park. One person pointed her out as someone who had money. Fuller was forced into an alley where she was repeatedly kicked and beaten. The beating continued in a nearby garage and a long metal object was forced into her rectum.

One law enforcement official, who called the case "haunting," said Fuller fought back when the group attempted to rob her.

Law enforcement officials say they suspect that as many as 30 people may have seen her death.

U.S. Attorney Joseph E. diGenova said yesterday that more than 400 people were interviewed in connection with the case and that the investigation is continuing.

Charges were dropped yesterday against Lamont M. Bobbitt, Roland A. Franklin and Darryl Murchison.

Those indicted were: Calvin L. Alston, 20; James M. Campbell, 18; Timothy Catlett, 20; Alphonzo L. Harris, 23; Russell L. Overton, 26; Levy Rouse, 20; Felicia Ruffin, 17; Kelvin D. Smith, 19; Charles S. Turner, 21; Christopher D. Turner, 19; Steven L. Webb, 20; and Clifton E. Yarborough, 17.