There was an increased police presence at the school, though few confirmed details were released by officials.
The school was reportedly evacuated.
According to the sheriff, a 16-year-old suspect was apprehended within minutes and a 15-year-old suffered a single gunshot wound that left him with serious injuries.
The shooting reportedly happened in a bathroom at the school.
A message was also sent out to parents and guardians of students at the high school confirming that the two involved knew each other, and that a weapon was brought onto campus that was used in the incident.
More information is expected to be released.
This is a developing story. Check Daily Voice for updates.
Want breaking news in the DMV as it happens, or want to contribute? Join the DMV All Incidents Facebook group.
Click here to follow Daily Voice Pikesville and receive free news updates.