Back up all assumptions. The problem must interfere with the student's education. After correcting the problem, follow up by noting improvements. Keep the parents informed of any changes. In the file, show the positive behaviors as well as the negative ones.
Parents can offer a dissenting opinion if they disagree.
The core content is what needs to be taught to the students. JCPS, or whoever hires the teacher, provides expectations and curriculum that explains what to teach and how to meet the expectations. Students need to be on a certain level at each grade. By fifth grade there is so much students should know. So by the time students graduate from high school, they should know have the skills needed to be productive to society.