D.C. Department of Human Services officials blamed staff negligence yesterday for the escape last month of a 17-year-old resident of Oak Hill who later was charged with two counts of first-degree murder.

Officials said that "appropriate disciplinary action," including the possibility of firing, may be taken against the employe, who was identified by sources as a secretary who was temporarily supervising Carl S. Richardson during the time he escaped Sept. 27 from Oak Hill's infirmary at the nearby Forest Haven institution in Laurel.

Richardson, who has escaped three times this year from Oak Hill, the city's maximum-security juvenile detention facility, apparently left through an unlocked fence door in the infirmary's yard when the secretary escorted another youth to the bathroom, according to an internal incident report at the institution.

Richardson was charged last week with an Oct. 7 slaying and another on Aug. 6, which apparently occurred after his June escape from Oak Hill.

The secretary, who is not normally assigned to supervision duties, said in a confidential statement that it was her first time in the yard and that she was unaware of a "hidden door" in the fence.

Some juvenile officials questioned yesterday whether it was appropriate to allow a secretary untrained in juvenile detention practices to watch a known "escape artist" and then blame the employe for not performing the job adequately.