A teenager accused of killing three schoolmates and wounding three others in a high school shooting in northeastern Ohio last year has pleaded guilty to murder and other charges in the case.

T.J. Lane, who authorities said was the shooter at Chardon High School on February 27, 2012, pleaded guilty Tuesday to three counts of aggravated murder, two counts of attempted aggravated murder and other weapons charges.

Sentencing has been scheduled for March 19.

Authorities said Lane, 17 at the time, admitted taking a .22-caliber gun and a knife into school and firing a number of rounds in the cafeteria, choosing his victims randomly.

When the violence ended, six students had been shot, and in the following days, three died: Daniel Parmertor, 16; Demetrius Hewlin, 16; and Russell King Jr., 17.