The attorney should determine if urine specimens were taken in a constitutionally prohibited manner and whether test results were derived from nonspecific drug tests. The reliability of the chain-of-custody procedure for the specimen must be ascertained, and the testing techniques used should be accepted in the American scientific community. Other factors important to the defense are test results without supporting quality control data, improperly interpreted test results, test results with concentration levels consistent with 'passive inhalation' and 'passive ingestion' of the controlled substance, and false-positive tests. The defense attorney may also consider the additional issues regarding the desirability of retesting, tissue typing, and blood grouping tests which may or may not assist in client representation. 52 footnotes.