D.C. Mayor Anthony A. Williams vowed yesterday to aggressively enforce the city's new youth curfew, as questions persisted over how police will handle the workload and where and how long violators will be detained.

Police officers made their usual rounds after the curfew began at 11 p.m., occasionally slowing down to shine spotlights on street corners to see if anyone looked younger than 17. But things seemed quiet in the first hours of the new policy.

Officer Leroy Williams brought a 15-year-old youth into the 7th District police station in Southeast Washington after finding him with older men in front of an apartment building. Williams called the youth's mother, who picked up her son at the station. The woman and her son said they hadn't known about the curfew.

On Second Street SE, Officer Eddie Woodward stopped his patrol car at an apartment where Gloria Corbin, 22, was in the courtyard with her 6-year-old daughter, DeShayla, on her back.

"I hope it works," Corbin said of the curfew, noting that many youths hang out on a nearby street. "A lot of young kids now, they're out here without control, no rules, nothing."

But some people--including police officers--questioned aspects of the new policy.

"How do you go about ID-ing these kids and finding out who's responsible for them?" asked Officer K.M. McConnell. "What do you do?"

McConnell's partner, Officer H.D. Newman Jr., said youths could lie about their age, or falsely claim that they were running an errand for their parents.

"There are so many loopholes," Newman said as the partners sat outside a convenience store off Benning Road NE. "You want us to be everyone's problem solvers, but you won't give us the tools."

The curfew prohibits youths age 16 and younger from being in public places after 11 p.m. Sundays through Thursdays and after midnight Fridays and Saturdays. The restriction is to be lifted each morning at 6 a.m.

The curfew is the result of a four-year-old city law that was challenged in court by critics who complained that it violates the civil rights of youths and could lead to selective enforcement--particularly affecting minorities in low-income areas. After three years of legal wrangling, an appeals court gave the city permission to enforce the law.

And so the District joins nearly 300 other U.S. cities that have turned to juvenile curfews as a way to try to better control crime problems that analysts say are fueled by wayward youths. Like many such initiatives, the District's plan seeks to round up curfew violators and take them home to their parents, who are being counted on to share in the enforcement.

But as critics have pointed out, many youths are on the streets late at night precisely because they are getting little direction at home. So what happens when a youth's parents cannot be located?

At that point, city officials say, police officers will try to take the youth to the home of a relative or other "responsible" adult friend. If that is not possible, the youth will be held at a police station until a parent, legal guardian or other responsible adult picks up the youth. Those youths who are not picked up by 6 a.m. will be handed over to the D.C. Child and Family Services Agency.

That plan ' has drawn criticism from the local American Civil Liberties Union, which had challenged the law in court. Mary Jane DeFrank, executive director of the local ACLU, said the city's enforcement plan puts a heavy burden on patrol officers to decide what to do with violators, and she questioned how the city's social services system plans to handle what she said could become a significant problem.

D.C. Council member Jack Evans (D-Ward 2), a curfew supporter, acknowledged that D.C. police will have "tremendous discretion" in enforcement.

"We have to rely on our officers not to harass, not to arrest and not to abuse a privilege they now have," Evans said.

Mayor Williams and Police Chief Charles H. Ramsey said the curfew is a critical part of their strategy to reduce nighttime violence.

"We're going to be working this program very aggressively," Williams said. "This curfew law will take our children out of harm's way during potential harmful, dangerous hours." Ramsey added that 16 of the city's 153 homicide victims this year have been juveniles.

Youths found in violation of the curfew eventually can be ordered to do 25 hours of community service. But the law is directed more toward parents and guardians, who can face fines up to $500 and be ordered to perform community service or undergo counseling.

The law has several exceptions, including emergencies, errands requested by a parent or guardian, travel to and from work, and attendance at school events.

At a news conference yesterday with Williams and council members Evans and Harold Brazil (D-At Large), Ramsey said enforcing the curfew will be "a drain on resources . . . but it's a step in the right direction for at least making some parents take a little more responsibility for their children."

Ramsey said that once curfew violators are taken to a police station, they will be housed in "community rooms," away from adult prisoners.

Gayle Turner, administrator of the Youth Services Administration, said she will meet with police officials Monday to discuss the curfew's potential impact.

Until then, Turner said, if police pick up any youth whose parents aren't home or can't be found, the youth will be taken to the Superior Court social services intake office. There, a decision will be made by the 24-hour office run by D.C. Superior Court to either detain or release the youth.

If the youth is detained because of a curfew violation, Turner said, the agency may send him or her to a temporary overnight youth shelter, used primarily for runaways.

Karen Kushner, spokeswoman for Child and Family Services, said that all children under 12 would be handled by that agency, with paperwork also going through the social services intake office.

"If the police can't locate a parent, relative or responsible adult by 6 a.m.," she said, "the child will be considered abandoned."

Staff writers Sari Horwitz, Allan Lengel, Phuong Ly and Valerie Strauss contributed to this report.

CAPTION: Police Chief Charles H. Ramsey speaks at a news conference. Behind him are Mayor Anthony A. Williams, left, and D.C. Council member Harold Brazil.