Parents and school staff sounded shaken during conversations with police related to an Aug. 27 shooting at Perry Hall High School.
Baltimore County police released recordings of 21 service calls on Monday.
School staff members who called police for assistance sounded panicked and distracted, as they attempted to control the scene while relaying relevant information to police.
Police lines were also "overflowing" with calls—as one officer can be heard saying—from parents of Perry Hall students and their friends. One parent said to police that Robert Gladden, who was sentenced to 35 years in prison on Monday, for the attack, had told her son to leave ahead of the shooting.
"I just told him to run," the mother said.
Calls from the media, and one from an administrator at another school inquiring about lockdown procedures, rounded out the remainder of the calls.
Last week, Gladden, 15, pleaded guilty to the attack, which left special needs student Daniel Borowy seriously injured.