The incident was targeted and is believed to have started with an argument earlier in the day on Tuesday, Feb. 8, police said.
It ended with a 16-year-old boy being shot in the shoulder in a parking lot after school let out Baltimore County police said.
He was rushed to the hospital with non-life-threatening injuries, Baltimore County police said. The school was briefly placed on lockdown.
Patrols were beefed up at the school Wednesday morning for an ongoing investigation.
A suspect is being sought. Anyone with information is asked to call 410-307-2020 or Metro Crime Stoppers at 1-866-7LOCKUP.
Click here to follow Daily Voice Towson and receive free news updates.