The two incidents reportedly took place on separate occasions last month. Rohrer also gave his resignation October 31.
In his letter, Rohrer states, "There are no logical reasons that excuse my judgment and actions against two students in the school."
Rohrer's personnel file indicates allegations were made against him before.
In October of 2012, Metro officials said they believe Rohrer used "an improper restraint technique" against a student. Staff members who witnessed the incident described it as pinching in the nerves under the armpit.
Marcia Northern has been named acting principal at the school.