Zero tolerance laws must be abolished. They are judge, jury and executioner all in one. No due process and no right to a defense. Each of which is guaranteed by the constitution. No public entity should have the power to pass such laws, rules or policies.
Many schools have adopted zero tolerance policies, some of which are overly broad and have resulted in the suspension or expelling of innocent students. Recently, schools have begun extending these policies beyond the school grounds and even now into people's own front yard
"http://reason.com/blog/2013/09/23/students-suspended-for-playing-with-pell"
Any violation of any law, rule or policy must be made on a case-to-case basis, not a zero-tolerance basis, so that the accused is not denied their constitutional rights.