Multiple reports out of criminal justice and the medical community repeatedly recommend Random Testing Programs, also meaning varying drugs are to be tested.
“Smarter drug testing means an increased use of random testing rather than the more common scheduled testing. In addition, smarter testing means testing based upon clinical indication for a broad and rotating panel of drugs rather than testing only for the traditional five-drug panel.” (Study by the American Society for Addiction Medicine/ASMA)
The ASMA report indicates that drug abusers will always look to subvert the test if they are not on board with reforming their own habits and improving their life circumstances.
The American University, Drug Court Clearing House Report for the US Department of Justice on benefits of random testing further bolsters this report: “Random Testing prevents participants from planning ahead and avoiding detection.” They cite the need to randomize all procedures.