A suspect, a 21-year-old man, was shot by police during the incident and was in extremely critical condition at Temple University Hospital, police said. Two other suspects were in custody, police said.
The incident began about 9:50 p.m., when a woman flagged down Roman and another SWAT officer, saying that three men in a white Chevy Impala had pulled a gun on her.
The officers found the car at the BP station, approached it and asked the men to show their hands, Ross said. They didn't comply.
Roman's partner saw the men fidgeting inside the car and thought he saw a weapon, said a police source who had been at the scene. The officer shouted "gun!" and fired his weapon, striking Roman and the 21-year-old.
Police aren't sure if Roman was shot directly or if a bullet ricocheted off the car. None of the suspects fired any shots but two handguns were recovered at the scene.
Though Roman was shot in the chest, the vest prevented serious injury.
"He just had the wind knocked out of him," Ross said.
This latest scare occurred in what has become a particularly perilous summer for cops.
The city just buried Officer Moses Walker Jr., who was the fourth Philadelphia cop to die violently this summer when he was shot during a robbery after getting off work Aug. 18.
Officer Marc Brady, 32, was riding his bicycle when he was struck deliberately by a car, authorities say.
Officer Brian Lorenzo, 48, was killed July 8 when he was riding his police motorcycle home from work and struck head-on by an alleged drunken driver.
Officer Milan Merke, 28, died six days after he was involved in a motorcycle crash while off duty on June 8.
Contact Morgan Zalot at email@example.com or 215-854-5928. Follow her on Twitter @morganzalot. Read her blog at PhillyConfidential.com.