The teen suspect, identified as Darryl Lanier, has been charged as an adult by the District Attorney's Office. The charges include Attempted Murder, Aggravated Assault, Simple Assault, Recklessly Endangering Another Person, Burglary, Conspiracy, Criminal Trespass and gun charges.
Lanier was arraigned Friday afternoon and bail was set at $2-million.
Officials say the suspect surrendered around 5:20 p.m. accompanied by his family.
Authorities had been in touch with the boy's father and helped negotiate his surrender. It capped a day of intense investigation.
For more than 24 hours police had been working to identify the shooter and make an arrest. They say SEPTA's state-of-the-art surveillance system provided them with crystal clear video of the gunman in action.
"It's huge. It's very good video," said SEPTA Transit Police Chief Thomas Nestel. "The shooter made a serious mistake yesterday shooting at someone. But he really made a mistake shooting at someone on SEPTA property."
Just before 2:00 p.m. Wednesday, a fight broke out among students onboard the subway on the southbound Broad Street line approaching the Susquehanna-Dauphin station.
Police say the video clearly shows what happened after the subway came to a stop.
"The offender exited the train, turned around, and fired into the train," said Nestel.
Bullets struck a 17-year-old boy in the arm and a 14-year-old boy in the leg. On Thursday police took that video to schools in the area, asking staff to help them identify the gunman.
"The shooter made a serious mistake yesterday shooting at someone. But he really made a mistake by shooting someone on SEPTA property."
The video was instrumental in helping to identify Lanier, said to be a teenage high school dropout.
Police say if you commit a crime on a SEPTA train, you will get caught. Each train car is equipped with ten cameras, and each station has anywhere from 15 to 50 cameras.
Every weekday, SEPTA police overlap shifts to allow for extra patrols in the afterschool hours. They always stay in close contact with the school district, so they know if school-related problems are headed their way.
SEPTA riders said Wednesday's shooting made them uneasy. But it won't change when or where they ride the SEPTA rails.
"Just one of those things," said Thomas Howard of North Philadelphia. "Something that can happen any time. It's not going to stop me from riding the subway."
"You have to be aware of your surroundings everywhere you go," said Charles Crowder of Center City, "because there is so much violence around."
The 17-year-old victim from Fels High School was released from the hospital on Thursday. The 14-year-old from Hartranft High remains hospitalized in critical condition. The bullet went into his hip and lodged in his stomach.