There were 18 shots in all.
The pellets destroyed more than a dozen windows, shattering the front door of the still new landmark in this river town of 33,000.
No one was injured as City Hall was closed around 10:30 p.m. when the gunplay went down.
Police are scouring any relevant surveillance video they can find, but no smoking gun yet.
"I'm treating it as a singular event. In the event, there's something more to it, I'll bring outside agencies in and we'll prosecute who needs to be prosecuted," Chester Police Commissioner Joseph Bail, Jr. said.
For Chester's new mayor John Linder, a Democrat sworn-in less than a week ago, this is troubling to say the least.
"We won't tolerate this. It won't go unresolved. We won't stop until we find the people who did this," Linder said.
In addition to all the problems of violence and poverty in this town, there is a great deal of political intrigue that plays out beneath the surface. There is some speculation that this may have been more than stupid vandalism.
Quietly some around City Hall are suggesting that perhaps it was an act of intimidation, but Chester's top officials are downplaying that as the investigation continues.
"What prompted it? I have absolutely no idea. It was not connected to any other events we know of that were happening in the city," Mayor Linder said.
"I don't want to speculate that it was political intimidation. Right now, it was a childish act and we're treating it as malicious mischief," Commissioner Bail said.
One local clergyman, Richard Dalton, Action News spoke with finds the gunfire deeply disturbing.
"It could have been juvenile delinquents. It's an indication that something's wrong with Chester," Dalton said.
The shooting occurred on a night when several local churches were holding anti-violence prayer services.
The search for the culprit continues as the city prepares to replace the expensive window at City Hall.
