I feel like there may be a correlation between all the students of the same class in school became evil. Sounds like the school's fault if you ask me.
Also rehabilitating them should be a teacher's job, not an assassin's, if they want this approach, why not assign a passionate teacher with expertise in the area?
And wth do they mean, "want to try a different approach", as if they have never tried anything aside from murdering innocent children. If they could change the future with murder, then it means the future can be changed, so methods should be flexible.
It's clear these kids are at least a little motivated to improve, yet they don't bother with lessons. They have solidarity as classmates, yet scorn the act of class itself. Even if they think the teacher is half-assing it, at least they're trying to teach according to curriculum, right? And just that would be better than self study alone anyway.