Nearly a third of the 223 juveniles who have absconded from city-sponsored group homes and shelters in the past three years are still at large, and almost two dozen of them have been at large for more than two years, according to an investigation by the D.C. inspector general.

In a letter to the head of the Youth Services Administration, the interim inspector general, Austin A. Andersen, said the youth agency's efforts to track down teenagers are "minimal and ineffective," and he urged "quick and determined" action.

Joshua Ross, 20, charged last week with killing Myesha Lowe, 15, had been a fugitive since he skipped out on a group home more than two years ago, according to confidential records.

The problem is not new, and the investigation has been underway for months as part of a broader examination of the city's juvenile justice system. A final report is still weeks or months away. But Andersen took the unusual step of issuing a preliminary report of his findings because he said the problems demand the immediate attention of the city.

Last summer, after a series of articles in The Washington Post exposed the scope of the problem, Mayor Anthony A. Williams (D) promised reforms. He eventually ousted the head of Youth Services, Gayle L. Turner.

The agency is still without a permanent replacement, and D.C. Council member Kathy Patterson (D-Ward 3) said the inspector general's report makes clear that little has changed. "The kind of progress promised a year ago has simply not been made," said Patterson, who chairs the council's Judiciary Committee.

Council member Sandy Allen (D-Ward 8), chairman of the Human Services Committee, said she plans a hearing on the report when the council is back in session.

Marceline D. Alexander, the interim Youth Services administrator, and her boss, Human Services Director Yvonne D. Gilchrist, declined to comment, as did Andersen. All said it would be inappropriate to comment publicly before the report is final.

Late yesterday, City Manager Robert C. Bobb said the city has been making progress on the problem and would be adding people to the effort. "We have greater coverage now than we ever had in the past," he said. By September, he said, five Youth Services employees would be working with four police officers to locate fugitives.

The report comes as the city is grappling with a spike in violent crime involving juveniles, from deadly joyriding to deadly shootings.

Just last week, David McMorris 16, was fatally shot on Georgia Avenue NW, allegedly at the hands of a 14-year-old, who has been charged with murder. And yesterday, in pleading guilty to manslaughter, a 16-year-old admitted that he was driving the stolen minivan that killed a 21-year-old man last month in Southeast.

So far this year, 17 people under age 18 have been killed, and the mayor, the police chief and other city leaders have been under pressure to curb the violence and to craft long-term solutions for the social problems that underlie it.

But the city's ineffectiveness at bringing in wanted juveniles is a chronic problem.

The inspector general found that the problems start when juveniles are first assessed. Those classified as high-risk offenders typically are recommended for placement in Oak Hill, the city's secure juvenile detention facility in Laurel, while those classified as low-risk offenders usually are placed in unsecured facilities, known as shelter homes or group homes.

But city investigators found that some hardened youth offenders with long criminal records were being improperly classified as low risk and placed in unsecured settings. From such facilities, "they can easily abscond and resume their criminal behavior," the report said.

With 188 beds, Oak Hill is frequently near or at capacity, and some critics of Youth Services, which operates Oak Hill, have said the agency may be using the classification system to limit the number of juveniles sent there.

Once offenders have absconded, the system for tracking them down is ineffective, the investigation found. A protocol drafted last year calls for every absconded youth to be the subject of a field investigation by a newly formed Youth Services unit. But from August 2003 to April, such investigations were conducted in only 20 of the 68 pending absconder cases, the investigation found.

Employees told investigators they were reluctant to do such investigations on their own because they lack arrest powers and the training for such assignments. But the investigation found that Youth Services has not taken advantage of available assistance, in particular from the D.C. police.

Once a judge has signed a custody order, as warrants for juveniles are known, the police can pick up the teenager. The report says that such orders have been obtained for all 68 youths still at large. But Youth Services employees said they provide a name to police only after Youth Services has located the offender.

And even if a juvenile is located, the report says, Youth Services cannot supply police with a photograph because the agency doesn't take any when it processes a youth.