It is againast the law to operate a vehicle with marijuana in your system. A police officer must have a valid reason to conduct a stop of a car and must have probable cause to believe that she was under the influence in order to arrest her for DUI and ask for a blood test. Zero tolerance is not a legal phrase and therefore, will not have a bearing on your daughter's case. You should consult an attorney as soon as possible.
**This response does not constitute legal advice and does not establish an attorney-client relationship.
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