How did they do? Why did they do it? I do not know what their reason was for doing it, except it might have been done to fill in the statistics. How they did, I will tell you what I know.
Each teacher will pick out students in their class rooms who they want to turn into problem children. They do more than turn them into problem children, they turn them into scapegoats.
The teachers will accuse a student, either out of their own invention or from the word of another student. The teachers then gives the future scapegoat no defense. It doesn't matter how truthful or convincing the student is, the teacher will rebuke it with some bogus explanation of why they are guilty. The punish the student for trying to defend them-self by making their punish worse and worse as they continue to fight in their defense.
The teacher keeps doing this to the same student, day after day. This makes the pain worse and worse. Eventually the student just accepts the punishment without trying to fight it. They become hopeless and without a defense, and unwilling to defend them-self, believing they have no chance. When the student gets into that condition of mind, the teacher will reward them by not being as hard on them.
This type of reward and punishment, and false accusations goes on day after day, for many years.
Now when they are accused by a police officer, or a judge, or any authority figure, they will not fight it. They will only give in and take the unjust punishment. These people are accused of molestation, murder, rape, theft, assault, violation of probation. And these people have done none of it.
The school staff and the judicial system work together for the creation, and harvesting of these people. One of the way they have taken away their defense, is to judge them based on past records. The mentally ill is where you will find most of these victims.
The school has been doing this to the students long before I attended school 30 years ago.