It happened near West 71st Street around 8:45 a.m. Friday.
Investigators say the workers were hanging out on a bench in the park when the homeless man began acting strangely.
Police say an argument between the group turned physical, and that's when the suspect pulled out a gun and fired three rounds.
No one was hit but the shots scared residents in the neighborhood.
"There was a lot of panic and it's obviously the heart of the Upper West Side so people were very worried," resident Sean Morrison said.
Authorities say they recovered a weapon when they arrested the 33-year-old suspect.
Few other details were released.
----------
* Get Eyewitness News Delivered
* More Manhattan news
* Send us a news tip
* Download the abc7NY app for breaking news alerts on the go
* Download our connected TV app