School had just started Monday for the year.
A suspect approached the 17-year-old victim during the release. The encounter became heated and the suspect pulled out a firearm, Baltimore Police Commissioner Michael Harrison said at a news conference on Friday.
The suspect, also 17, shot the victim several times, Harrison said.
The suspected shooter ran down the street and school police arrested him after a short pursuit without “incident or injury,” Harrison said.
Authorities also seized a firearm that the suspect discarded, he said.
School police performed CPR at the scene on the student, who had life-threatening gunshot wounds, the Baltimore Police Department said in a written statement. The victim was pronounced dead shortly after arriving at a local hospital, the statement said.
“This is an extremely tragic situation, more than tragic, to occur on a school campus at the beginning of the school year,” Harrison said.
The person taken into custody is a student at another high school in the city, according to Harrison. Police have not yet named the victim or suspect.
Baltimore City Public Schools CEO Sonja Santelises thanked police officers for arresting the suspect “within seconds of the incident.”
The school’s safety plan is in place and school police are “on duty” during the release, Santelises said. Police also said police were in the school yard during the shooting.
After the violent incident, Santelises, along with Baltimore Mayor Brandon Scott, met with some students, according to CNN affiliate WBFF. Extracurricular activities have also been canceled, according to Baltimore City public schools. A large number of students witnessed the shooting, Santelises said, and the school system is offering grief counseling next week, WBFF reported.
Harrison said the investigation is still ongoing and asked the public to contact police with any information.
Friday’s shooting is the latest incident of violence at the school, also known as Mervo. In April, a student stabbed two classmates during a fight, the WBFF reported.