A D.C. policewoman who claimed last May to have found an abandoned baby girl in the stairwell of her apartment building, then admitted six days later that the infant was hers, has been fined by a police trial board but was allowed to remain on the force, police officials announced yesterday.

Connie Hickman, 29, an 11-year member of the force assigned to the 7th District, was found guilty on three departmental charges and fined $1,350, according to Inspector Richard J. Pennington, chairman of the trial board.

The board, which noted "mitigating circumstances surrounding the stress and personal situation of Officer Hickman," recommended to Chief Maurice T. Turner late last month that she be allowed to "continue being an asset to the police department." Turner accepted the recommendation Friday, police officials said yesterday.

Hickman had been charged in the incident with conduct unbecoming an officer, making an untruthful statement to a superior and conduct prejudicial to the police department after the U.S. attorney's office declined to bring criminal charges in the matter.

According to police accounts, Hickman claimed May 18 to have found an newborn baby girl wrapped in a sheet under the stairs in her apartment building in the 3700 block of Ninth Street SE.

The story received widespread media attention, and police investigators said that they soon began receiving information suggesting that Hickman, who had been on sick leave for four weeks suffering from a broken ankle, had appeared to be pregnant before she reported finding the child, according to testimony before the trial board.

Six days after she had claimed to have found the baby, Hickman admitted publicly that it was hers, saying that she had fabricated the story because she did not think she was capable of supporting the child in addition to her three other children.

In testimony before the three-member police panel, Dr. Laurence Cove, a psychiatrist, said he found "no evidence" that Hickman suffered from psychiatric problems, but he said that she had fabricated the story "in a moment of stress." He said Hickman had delivered the 6-pound, 10-ounce infant by herself in her apartment, then called police two hours later and said she had found it.

"I knew she would be taken care of, somebody would want her," Hickman told the trial board. "I wanted her, too, but I couldn't take care of her . . . . I didn't have any money," she said. "So I knew . . . that if I said she was abandoned, someone would take good care of her."

Testimony showed that Hickman returned from sick leave to work "light duty" several months ago.

Pennington said, "While it is our job to maintain the integrity of the police department . . . because of the testimony we showed compassion for a fellow human being."

Hickman's attorney, Robert E. Greenburg, said that, because of Hickman's financial circumstances, he plans to appeal the fine to Turner.