CHAPEL HILL - Police released a surveillance photo of a fourth suspect in the June 18 Greenbridge vandalism case but had made no additional arrests as of Friday.

In an interview, Mayor Mark Kleinschmidt said the town needs to prosecute those who damaged the Greenbridge lobby to send a message their behavior will not be tolerated.

The protesters crossed a line when they entered the building, spraying Silly String, damaging the floor and art work and blocking elevators, Kleinschmidt said.

"At the end of the day, they invaded people's homes," the mayor said. "I would imagine in a reasonable person this would invoke a large amount of fear."

No group has claimed responsibility, and the three people arrested on felony and misdemeanor charges have declined to be interviewed.

Infoshop News and other political websites described some of the protesters as anarchists.

A photo on several websites shows protesters holding a red banner that says "Total War on Gentrification" with the letter "A" inside a circle, an anarchist symbol.

Kleinschmidt said anarchists come with the territory in a college town, where people tend to tolerate a wide range of beliefs.

"I think there's an appropriate limit to that tolerance," he said. "We need to prosecute this kind of behavior to send a message this is intolerable."

Chapel Hill police say most of a group of about 20 people inside the downtown high-rise ran out a side door before they could be stopped.

Police reviewed video footage from the lobby last week but so far have released just one suspect photo. (See photo, page 4)

"Many of the individuals had masks or something covering their faces, so it may be difficult," said Lt. Kevin Gunter.

The suspects arrested - Brian Dingledine, 37, of Chapel Hill; Karoline Knable, 26, of Durham; and Kyle Whisenant, 27 of Greensboro - have been charged with felony rioting and misdemeanor property damage.

Total damage was estimated at $3,400, including $2,000 damage to a tile floor and $1,000 damage to artwork knocked off the wall, according to police reports.

Police Chief Chris Blue said the behavior was unusual for Chapel Hill. Demonstrators have been arrested in recent years - protesting issues as diverse as Army recruiting and tomato pickers' wages - but typically because police said they failed to stay on public sidewalks or heed instructions to disperse.

"I think it was scary behavior, certainly upsetting for the staff who were understandably surprised and shocked when a mob descended on the lobby," Blue said.

High-profile project

Greenbridge, a $56 million pair of seven- and 10-story buildings on West Rosemary Street, has received acclaim for its special heat pumps, green roofs and other features that cut its energy consumption to half that of similar-size buildings.

Critics say the project is speeding gentrification in the historically black, working-class Northside neighborhood across the street.

Census data, however, shows Northside has been losing black residents for decades.

The Town Council adopted a temporary building moratorium Tuesday night to try to slow the spread of student rentals there.

"Greenbridge is a convenient scapegoat for what had already occurred in the west end of Chapel Hill decades earlier," Greenbridge partner Tim Toben said Tuesday.

Northside homes were purchased as investment properties and rented to students in the 1970s; by 2001, a study showed the neighborhood was already 71 percent "gentrified," primarily with student rentals, he said.

"The incident that occurred last Saturday was no peaceful protest," Toben said. "I am all for freedom of speech and peaceful protest. They are rights that I also exercise.

"The behavior of the anarchists is unlawful and based on unfounded assumptions."