About 100 people were in the area, and nobody was injured, said police spokeswoman Laura Wohl.
Investigators think the man might have attempted to break up a fight on the sidewalk, Wohl said.
“The men who were fighting then turned on the suspect and punched him in the ribs,” Wohl wrote in a news release. “The suspect moved away from the altercation, pulling a handgun from his pocket and pointed it at the crowd on the sidewalk. He fired at least two shots in the air before witnesses and police detained him.”
The man did not appear to be under the influence of alcohol or drugs, Wohl said. He is being held for investigation of second-degree assault, she said.
