A group of Harlem residents donned paint clothes yesterday and joined the speaker of the City Council, Christine Quinn, Reverend Al Sharpton, and other local officials to obliterate a piece of pro-violence graffiti.

Before yesterday, the wall of a Harlem bodega on 110th Street bore the image of a rat with a noose around its neck saying, “Stop snitching.” But that message keeps killers on the streets, Cherise Smith, who lost her 15-year-old son, Nathan Allsbrook, to a stray bullet from an unknown shooter on June 29, said.

“We’re still looking for the person, and people don’t want to tell. People think they’re snitching,” she said. In encouraging community members to come forward with information about violence rather staying silent, she said, “it’s helping a parent to feel at least that this person cannot get away for what they have done.”

Ms. Quinn gave an ultimatum to propagators of the “stop snitching” message. “Anywhere you go with paint, we will follow you with paint,” she said. “We will go to every borough, every block where someone dares to cause fear.”

Rev. Sharpton said members of communities couldn’t afford to shield each other. “You can’t say, stand up if we are discriminated against, that’s testifying, but if we do it to each other, that’s snitching,” he said. “Crime is crime no matter who the criminal, no matter who the victim.”