The Two Lightning Bolts

Riddle: Dorothy and Irene are now model citizens, but in their younger days, when they were in elementary school, they were known as "The Two Lightning Bolts". It was the last day of fourth grade for these two classmates back in 1929, and the two had concocted an evil plot to get back at their fourth-grade teacher, who they did not like. At one point, when the teacher turned his back on them to face the blackboard, Dorothy and Irene each carefully removed loaded guns from their lunch boxes, aimed them at the teacher, and pulled the triggers. Fortunately, they were both poor shots, but they did manage to graze their teacher on his back and head with a few of their repeated shots. As the teacher tried to escape the classroom, he slipped and fell twice on Dorothy and Irene’s loose ammunition, but he managed to make it to the school office to report the shooting attack. However, "The Two Lightning Bolts" received only a two-week suspension, starting at the beginning of the following school year for their premeditated attack on the teacher. I always heard discipline was better and stronger in the past, but these two tried to shoot their teacher with loaded guns, and got off with only a two-week suspension! How can this travesty ok of justice possibly be explained?