Security guard Tyshon Hasty says it all started with road rage.
"I fired my weapon in return of him firing at me multiple times," said Hasty.
Philadelphia police say it started at 13th and Melon streets near the West Poplar Apartments around 2:00 Sunday afternoon.
Hasty, who works at a federal building in Center City, exchanged gunfire with a car full of men.
Investigators say the group of men were in a gray Buick Century with Delaware tags.
26-year-old Hasty, who's also from Delaware, was in his Mercury which is now covered in bullet holes.
He says he chased the men several blocks to the 800 block of Reno Place where the gunman jumped out and ran into one of the homes.
"I was just trying to keep eyes and give police information while I was on the phone with them the whole time," said Hasty.
Gail Thomas was the first to see the security guard with his gun drawn.
"He was standing in the middle of the street pointing a gun at every house on the row then he ran back and pointed the gun again and I said, 'Look at that man out there with the gun,'" said Thomas.
Police evacuated several houses and called in SWAT for the barricaded man. However, more than an hour later, officers moved in and didn't find anyone inside.
"We've got a lot of witnesses that we've taken statements from both at this location and at 13th and Melon. It's like a puzzle, we have a lot of pieces," said Chief Inspector Joe Sullivan.
As of yet, it doesn't appear that Hasty will be facing any charges. Police say his credentials and license to carry both checked out.
Meanwhile, the suspected gunman still remains on the loose. Investigators have not released his name.