The lesson this young man and others who have found themselves in this situation has nothing to do with the importance (snicker, snicker) of a zero-tolerance policy as it relates to the safety of students. It certainly is not about the truth and doing the right thing.
Lesson learned: Hide whatever it is, and hope you can get through the day without the offending item being noticed.
This young man and his classmates have learned that the adults in charge are going to nail them regardless. The adults in charge see no difference between an honest young man and a gangbanger.
The children have learrned that lying (even by omission) is the preferred course of action.
Color me surprised that I find myself agreeing with an ACLU'er, but I do. The next student will be strongly motivated not to self-report.