"At this time -- this is preliminary information and what we have is this was some type of argument ensued between a group of people," said San Francisco Public Information Officer Grace Gatpandan.
Police say the shooter ran North toward Fell Street and that's where he carjacked a getaway vehicle.
The stolen SUV is a silver Toyota Forerunner with the California license number 7AOB816.
Police say they don't know yet if the victims and suspect knew eachother.
People who frequent the park say it's not uncommon to see a group gathering near Stanyon and Oak streets.
"That spot right there has concrete, so it's like a little kind of grotto in the trees and there are often people there," said San Francisco resident Tiarie Irvine. "Often homeless people kind of just hanging out."
Investigators have not identified either victim, nor confirmed if either of the men are part of the homeless population from the area.
Stay with ABC7 News for the latest details on this developing story.