(CNN) -- A 17-year-old male was charged Saturday as an adult with aggravated assault and other charges over a shooting the previous day at a Philadelphia high school, police said.
The suspect, accompanied by lawyer, was taken into custody about 1 p.m. ET Saturday.
"The male that turned himself in ... has been deemed the shooter based on the investigation thus far," said Philadelphia police Lt. John Stanford.
Later Saturday, the suspect -- whom Stanford identified as Raisheem Rochwell -- was arraigned as an adult. He faces aggravated assault, violation of Pennsylvania's Uniform Firearms Act, recklessly endangering another person, having a weapon on school property "and other related charges," according to the police spokesman.
Rochwell's bail was set at $500,000, added Stanford.
Detective Don Suchinsky said Saturday that a second male held for questioning was released to his mother. Another juvenile was questioned and released Friday.
All this stems from a shooting that occurred about 3:30 p.m. Friday in the gymnasium at Delaware Valley Charter High School.
The shooter was in the school gym with about seven other students, city police Commissioner Charles Ramsey said. Some were playing basketball and others standing in a corner when he pulled a gun and fired.
The victims were an 18-year-old female and 17-year-old male, police said. She was struck in the rear of the left arm, with the bullet perforating her bicep and striking the boy in the shoulder. They were taken to a local hospital, police said, and their wounds are not life-threatening.
The incident was at least the second shooting at or near a school this week in the Olney neighborhood.
The school went into lockdown as law enforcement officers searched students and let them out of the school, said Stanford. They determined that it wasn't an active shooter incident.
The shooter had left the scene.
Not long after the lockdown, Philadelphia police posted a message on Twitter, saying they had a suspect in custody. They later released the 15-year-old male, who was "completely cleared by investigators," Stanford said.
On Saturday, police said school security officials provided inaccurate information about the teen who was cleared and released.
What exactly happened in the gym remains unclear.
"We don't know the motives," Ramsey said, "don't know if it was an accident, don't know if it was intentional."
Surveillance video captured the incident, Stanford said. But police do not know how many shots were fired, Ramsey said. No shell was found at the scene.
Police searched for the weapon late Friday in trash cans, along railroad tracks and other spots around a nearby major urban transit station, transit spokesman Andrew Busch said.
Commissioner Ramsey seemed frustrated about school shootings reported across America.
"People send their kids to school; they shouldn't have to pick them up at the hospital," he said. "These kind of things just absolutely should not happen."
CNN's Greg Botelho, Elizabeth Landers and Susan Candiotti contributed to this report.