"School Discipline Study Raises Fresh Questions"

"Minority students facing discipline for the first time tended to be given the harsher, out-of-school suspension, rather than in-school suspension, more often than white students, the study said. (The nature of the offenses was not noted.) "

The link I followed says that the Texas study raises questions.
I have a question. Which moron decided that the nature of the offense was not a major factor in this study? This could have been a valid study but I expect that the desired results were not achieved without skipping major factors. The whole thing should have started with the type of offense linked with the rest of the demographic factors. Perhaps there is an unfair racial bias that could be addressed but one should at least make the effort to put forth a defensible study.