It happened at around 2:30 p.m. on Thursday at Hope Avenue and Madison Street in Coatesville.
Jaki White-Marshall, 17, is now in custody. Authorities say he is a student at Coatesville High School.
He will be charged as an adult with with aggravated assault and other offenses.
The Chester County District Attorney Chris de Barrena-Sarobe also released new surveillance images of the suspects on Friday.
He said White was one of four people involved in the shooting -- a shooting investigators are now calling a "targeted attack."
"Our investigation shows this is not some sort of school shooting, or someone trying to shoot up a school bus, or drive by. This was a targeted event where the actors were targeting someone getting off the bus," said de Barrena-Sarobe.
The Coatesville police chief said the suspects were targeting someone getting off of the school bus.
Investigators said two of the four suspects fired two separate guns, and in total, eight shots were fired.
The school bus was hit twice: one in the bus grill and the other in the front window, sending glass into the driver's face.
The D.A. urged the suspects to surrender to police.
"My message to those three people is: get ahead of this. Go to your families, go to your religious leaders here in Coatesville, and come to the police department and turn yourself in," de Barrena-Sarobe said.
He said investigators have an idea of where the investigation is going.
"This is your chance to put the community at ease, because there is not a single child that should ever feel like their school bus is not a safe place," de Barrena-Sarobe continued.
The Coatesville Area School District superintendent told Action News that both the district's senior and intermediate high schools operated on a virtual learning schedule Friday out of an abundance of caution.
Teachers and administrators returned to the high schools Friday, while students remained home for virtual learning.
District leaders made the change after the incident on Thursday.
"I cannot describe what I feel for that driver. As a school bus driver, your main thing is to make sure that your students are safe," said Nikki Batt, from Downingtown.
The bus driver did just that.
The bus company, Krapf School Bus, tells Action News the driver called dispatch who then called the police. Officials say she then drove about two miles to the Westwood Fire Company, where parents were eventually able to pick up their kids.
"She kept those kids safe. She kept herself safe and she made sure that she got away from the situation like she should have," Batt said.
Investigators said no one was injured.
"Students on the bus are safe, as is the driver, and police are on the scene. We are extremely grateful for the calm reaction of our driver and the support of police," the school district said in a statement.
"We prepare and train for a lot of things but being in an active shooter situation is not one of them," Batt said.
The community was rattled by the incident.
The shooting even led to the cancellation of the Coatesville Area Senior High School football game against Downingtown East that was scheduled for Thursday night.
"Hopefully, it doesn't happen again but in today's society and world, can we ever be too prepared for anything," said Carmen Lemus, from Coatesville, who was set to transport kids to the game.
Investigators said this is a high-priority case and that they're working to catch those who are responsible.
Police have not released information on a possible motive for the shooting.
"No child should be subjected to gunfire on a school bus. This is an active, high-priority investigation," the Chester County District Attorney's office said in a statement.
Anyone with information is asked to call the Coatesville City Police Department at 610-384-2300.
Read the full statement from Krapf School Bus on this incident:
"Krapf School Bus has been transporting school students for over 80 years. From the beginning, the safety of our passengers has been our number one priority. To that end, all driver and monitor candidates undergo thorough pre-employment background checks and rigorous training. The Krapf new driver training program far exceeds state requirements, both in the classroom and behind the wheel, as does our ongoing veteran driver training and recertification program.
Regarding the incident that occurred at Charles Street in Coatesville, PA on October 10, 2024. Our bus was struck by gunfire. Our driver immediately drove our bus away from the scene to a safe location. Our driver contacted dispatch who alerted the Police. Our bus was transporting students at the time of the incident. No one on the bus was injured. We are working closely with the local Police and the Coatesville Area School as part of the ongoing investigation.
Should you have further questions please contact Robert Jones of our Safety Department at 610-444-2030, ext. 2453."