Mayor Anthony A. Williams last night declared that juvenile car thieves have created a crisis in the District, and he pledged to add law enforcement resources and increase social services for the troubled families and neighborhoods in which so many of the offenders grow up.

"All of us agree that we have to put an end to this, an end to this madness," Williams said.

Hours earlier, teenagers in a stolen car slammed into a house while trying to elude police in Northeast Washington, terrifying a homeowner who was awakened by the crash. No one was seriously injured, but it was a frightening reminder of the accidents blamed on teenage car thieves that have left four people dead in the last month.

"These aren't just kids out for a joy ride," Williams said. "These are acts of reckless, senseless violence. These are crimes."

Under pressure from neighborhood residents -- including about 400 who turned out for a community meeting last night -- Williams (D) was determined to sound the stern tone that frustrated residents long to hear. But whether the rhetoric of Williams and other leaders will lead to results appears as uncertain as it was a year ago after two people were killed by juvenile car thieves.

Last summer, too, Williams attended meetings in east-of-the-river neighborhood beset by car thieves and pledged a comprehensive attack on the problem. Last night, he promised to do more.

Appearing at a school in Southeast, Williams acknowledged that the problem was far more than a crime issue, and the presence of his top social services official, Deputy Mayor Neil O. Albert, appeared intended to underscore that point.

Neighborhood residents have complained for years about juvenile joy riders, who race along streets in games such as "cops and robbers." The speeding cars often veer wildly from curb to curb through residential neighborhoods, particularly in areas near Anacostia Avenue and other busy streets in Northeast and Southeast.

Scores of angry residents showed up at Davis Elementary School for a news conference to outline the city's plans, hoping for a chance to address the mayor. Several stormed out of the school when told that they would not get a chance to speak. Williams was headed to a community meeting in Northeast to talk about the juvenile joy-riding problem, but people at the school were hardly mollified.

In Northeast, Williams faced a standing-room-only crowd at Zion Baptist Church of Eastland Gardens, where people expressed frustration with the city's inability to curtail joy riding. It was the second community meeting within the past several days, the first attended by the mayor.

"This is larger than any one of us," Williams told the people there. "It will demand divine guidance and inspiration."

The scene seemed a flashback to last summer, when the mayor went to another church -- First Rock Baptist in Southeast -- and vowed that city agencies would keep better track of errant youths and steer them from trouble.

Anthony Minter, First Rock Baptist's pastor, said he could not help but wonder yesterday whether this year's plan will go any further than last year's. "The real deal is a lot of the resources that were promised, it just never materialized," said Minter, who attended yesterday's news conference.

At the outset of last year's effort, city agencies were engaged and full of energy, but the effort soon fell off, starved of the commitment needed to make it real, Minter said.

D.C. Police Chief Charles H. Ramsey commissioned a study last year that showed that some car thieves keep cycling through the system. The review covered about 1,600 juveniles arrested in a three-year period that ended in 2003. It found that more than 670 of the youths had at least one prior arrest for car theft. About 300 youths had two or more prior car theft arrests.

The action plan outlined by the mayor last night has several elements: a more concerted and coordinated effort by police and prosecutors; changes in the law to strengthen deterrents; improving recreation facilities; installing street barriers and other traffic-slowing devices; increasing support to troubled families; and requiring more parental involvement and responsibility.

The mayor had planned to reveal his initiative even before yesterday's crash. That chain of events began about 3 a.m. after teenagers attempted to steal a car at a gas station in Seat Pleasant, police said. The car was owned by an off-duty D.C. police officer, who saw the youths speed off in another vehicle -- a white Lincoln Town Car that turned out to be stolen. The officer used his radio to broadcast a lookout for the youths.

D.C. police said they spotted the stolen car and began pursuing it at 61st and East Capitol streets. The teenagers wound up crashing into the picture window of a home in the 4200 block of Nash Street NE, police said. The homeowner got up from her bedroom and saw the youths running through the house.

The woman would not comment. But she agreed to relay her account of what happened through a friend. The friend quoted her as saying that she suggested to the youths that they go into her basement. They did, leading to a standoff with police that dragged on for about five hours.

Five 16-year-olds and a 14-year-old were arrested, police said. Police said they found a gun in the smashed-up Lincoln.

The woman's living room was a shambles: The crash wrecked a piano, antiques, china and other furnishings, the friend said.

The woman's neighbors said that juvenile car thieves are a frequent menace on the streets, where many elderly people live and homes have been in the family for generations.

In recent weeks, the residents said, young people driving stolen cars have struck utility poles, trees and chain-link fences along Anacostia and Kenilworth avenues.

"They're stealing the cars from other neighborhoods and using Anacostia and Kenilworth as a speedway," said Willie Bowman, 53, who lives on nearby Meade Street NE. "I sit out on my porch and I see them -- zoom, zoom."

The nights start quietly, Bowman said, but before long, the cars begin screeching and the police helicopters start hovering in hopes of tracking the young car thieves.

"Any time after 11 or 12 [at night] is when you hear the speeding cars coming through and the helicopters overhead trying to chase them," Bowman said.

Staff writers Theola Labbe, Allan Lengel and Del Quentin Wilber and staff researcher Bobbye Pratt contributed to this report.

Community activist Johnnie Scott Rice, right, confronts Mayor Anthony A. Williams because residents were not given a chance to speak at a gathering in Southeast.