Viola Keyes, the chief investigator in the D.C. Department of Human Services, was placed on administrative leave yesterday while the city's police and inspector general investigate charges that she ordered her staff to destroy records about deaths in city-funded group homes for the mentally retarded.

Police guarded the DHS investigations office into the night after a team from the inspector general's office, acting on a tip, secured files and interviewed staff.

"I take all allegations of this nature seriously," said DHS Director Jearline F. Williams, who suspended Keyes pending further inquiry.

Keyes, a city employee for more than 25 years, is the head of the DHS office responsible for examining abuse and fraud among agency employees and city contractors, including the city's group homes.

The Washington Post reported Sunday that DHS had lost or concealed records regarding dozens of deaths in its group home system, and that one case manager, Dwayne Franklin, had shredded documents about a suspicious death after The Washington Post asked questions. Franklin was fired last month. The Post examination revealed hundreds of instances of neglect in the community-based system and 116 deaths of residents since 1993.

D.C. Mayor Anthony A. Williams this week pledged full cooperation with federal and local investigators. Williams announced personnel changes and promised strong oversight of the city's 150 group homes, saying government employees "from top to bottom . . . will be held accountable."

Police officials, meanwhile, have assigned the investigation to the major crimes unit of the department and have met with the U.S. attorney's office, the FBI and the D.C. corporation counsel.

Although DHS officials had told The Post that deaths had been routinely investigated--and that certain deaths were referred to Keyes's office for special inquiry--Keyes's unit was unable to document, after months of inquiries, that it had completed a single investigation between 1993 and September 1999.

Jearline Williams questioned Keyes yesterday about whether she had ordered the destruction of several dozen case files, DHS officials said. Williams subsequently placed Keyes on administrative leave for the duration of the investigation. Keyes did not return repeated telephone calls.

Keyes, 55, has long been a controversial figure at DHS. A licensed social worker with master's degrees from Howard University and American University, she sued supervisors and the District government repeatedly in the past 12 years, alleging that she was a victim of age and sex discrimination and suffered retaliation for being outspoken.

In a 1993 affidavit filed in D.C. Superior Court, Keyes said she endured "atrocious, extreme and outrageous conduct." Asserting that she was wrongly removed from her job during a 1991 downsizing, then rehired at a level unsuitable to her skills, she maintained that the actions of the city and senior managers caused her "much emotional distress, embarrassment and humiliation."

Keyes sought $8 million. A Superior Court judge dismissed the case.

In an earlier case described by her attorney in court records, Keyes said she was demoted improperly in November 1987. She filed a complaint with the Equal Employment Opportunity Commission. With her federal trial underway, the District rehired her at her original level, wrote lawyer Robert Bell.

Outside the mayor's office last night, members of Capital Area Adapt, a disability rights group, placed candles and flowers in front of cardboard cutouts shaped like tombstones. On each cutout appeared the name of a retarded person who had died under the District's care, written in black ink.

"I knew most of these people who died," said Bernard Briggs, 40, a former group home resident. "It was a nightmare then, and it's still happening."

He wiped tears from his face.

Among other vigil-keepers, members of the District's Center for Independent Living program protested the deaths, which they said could have been prevented.

"I feel my brothers and sisters who died in the District programs did not get the respect they deserved," said Hannah Pittsgalmore. "I expect them to get quality care now."

Staff writer Emily Wax contributed to this report.

CAPTION: Jill Jacobs lights candles to set in front of cardboard gravestones bearing the names of the dead. Last night's vigil was in front of One Judiciary Square.

CAPTION: Tom Hale, center, joins a candlelight vigil to commemorate the deaths of disabled people in District group homes.