The photos clearly show the man's face and the clothes he was wearing at the time.
The shooting happened around 4:30 p.m. Tuesday on the 700 block of S. 57th Street.
According to Philadelphia Police Chief Inspector Scott Small, this all started when three young males boarded the bus without paying at 19th Street and Oregon Avenue.
"They had some words with the driver. However, the driver pretty much shrugged it off," Small said of the confrontation.
At 57th and Catherine streets, the suspects got off, and that's when police say one of them fired four shots into the passenger's side of the bus.
"Everybody just started screaming, 'Stop the bus, stop the bus!' And obviously, he didn't stop the bus because the shooters were right there," recalled a passenger who identified herself as Tori.
"I thought I was going to die for a second, so it's just weird," she added.
There were more than 50 people on the bus when the shots rang out, including a shooting victim's child, Small said.
Police say a 29-year-old was shot in the buttocks, a 56-year-old was shot in the back, and a 60-year-old suffered a graze wound to the side of her head. All three are listed as stable at an area hospital.
Anyone with information is asked to call Philadelphia police at 215-686-TIPS (8477).