According to this site, there is a background check that must be able to be passed to be able to sit for the examination itself. A candidate cannot have a felony record of any kind. Additionally, the candidate cannot ever have had a conviction for any sort of drug crime even if it is a misdemenor. It may vary from state to state. I looked at several schools requirements and they all mentioned having to pass a background check. Pharmacy technicians deal with private patient medical and billing information as well, so that has to be taken into consideration along with the access to narcotic medications.