Police officers respond to a call that an active shooter had reportedly injured 24 students at Chillicothe High School in Chillicothe, Ohio, in September. The call turned out to be a hoax. Similar scenes have played out at schools across the country in recent weeks. Chillicothe Police Department/Screenshot by NPR hide caption
This file photo released Feb. 15, 2018, by the Vermont State Police shows Jack Sawyer from Poultney, Vt., accused of planning "to shoot up" his former high school. AP hide caption
LA County Sheriff's patrol cars leave El Camino High School in Whittier, Calif., on Wednesday. A 17-year-old student threatened to open fire at the school days after the massacre at a Florida school. An alert security guard who overheard him reported it to police, who went to the boy's home and found two AR-15 rifles, authorities said Wednesday. Reed Saxon/AP hide caption