If you look around Swissvale, you might think the borough has a budding gang problem. But police deny it.

Between Friday night and Saturday morning, gang-style graffiti appeared on nearly a dozen buildings on Roslyn, Woodstock and Ardmore streets and Scott Way, an alley.

Several weeks ago, somebody flung a pair of high-top shoes over a utility wire at the corner of Roslyn and Noble streets, less than a block from police headquarters. Both, according to street gang experts, indicate the presence of gang activity.

As if in response, the graffiti appeared about a week after business operators met with borough officials to demand that the town curfew be enforced.

Mayor Deneen Costanza Swartzwelder, who is the Swissvale Crimewatch president, could not be reached on Monday for comment.

Police Chief James Ohrman said he was not willing to believe gangs are coming into town.

He said the tagging could be in retaliation for a Friday night police sweep which happened just before the properties were defaced. From 4 p.m. to midnight, Swissvale police, aided by several other law enforcement agencies, cleared the streets of people with outstanding warrants or who were subject to the borough's curfew.

Although the markings around town look like the stuff the Crips would throw up, Chief Ohrman said that was not likely the case.

"I don't feel that we have a home-based gang problem here," he said. "I'm optimistic. With all the shootings going on [in other communities], I think they are starting to see that that is not any kind of life to live. [But] if it starts to show up here, we'll hit it full force because we're not going to accept it here."

Chief Ohrman said, however, that the department would need outside help because his officers have had "minimal" training in confronting street gangs.

Leonard Butler, 34, lives in Swissvale, but grew up in the Hill District. His upbringing gave him an ability to recognize street gang signs.

He owns a few refurbished rental properties around the borough. On Monday afternoon, he and his partner, Carey Knight, were readying for tenants a Woodstock Street duplex that had been painted with graffiti.

He had set down his tools and walked outside to re-examine the words: "C'z Up" "Yung Ghutta."

"I'm trying to invest in the neighborhood and somebody does this," he said, gazing at the blue and black spray-painted letters on the brick building.

He said "C'z Up" is gang shorthand for "Crips Up." The words indicate the gang's intention to settle in the area or that members already have. The shoes hanging on the wire near the police station mean that the group has started or plans to start selling drugs in the community, he said.

Mr. Butler said he moved to Swissvale two years ago with his family to escape gang infestation.

"Growing up, [the graffiti] never used to bother me," he said. "But now that I'm an investor, I can see how it could [anger] people. I really don't know what I'd do if I saw somebody doing that."

Mr. Butler said teens needed a supervised hangout and that neighbors had to watch out for each other.

"The fact that they got so many buildings means that nobody in the neighborhood was paying attention," he said.

Richard Jefferson, 65, lives near a building whose white aluminum siding was covered with blue words reading: "Ghuttacide, C'z up, What up RoCC."

He said from his bedroom he heard the voices of a group of young people walking through the neighborhood after midnight Saturday.

He said he didn't look out the window as the noisy group passed, but he heard police officers ordering them out of the area.

"I don't think they're strict enough with these kids," Mr. Jefferson said. "They should put them in Shuman [Juvenile Detention Center] and let them see what it's like" to be locked up.