On Monday, the president of the Central Texas Association of Public Employees and a Bexar County probation officer said the high numbers of positives were alarming."Confirmation has come back to the department and we're concerned about those, and also, a lot of defendants on their own have gone out and had hair follicle tests in other labs to confirm their suspicions," Sheri Simonelli said.Here's another great example of the subjectivity of forensic science. In this case, there exist no concrete standards for how to measure urinalysis results. Reports KSAT, "Jeff Warner, the owner of Treatment Associates, said a test used before a February switch wasn't aggressive enough, and has led to a 35 percent jump in positive drug tests. He said the county's probation department was using an outdated test and an unguarded urine specimen process."
Normally one doesn't think of judging a scientific metric by whether it's "aggressive," but whether it's "accurate." I have no way of knowing which standard lies closer to the truth. But if a change in (unregulated) testing protocols resulted in such dramatic a difference in results, the disparity demonstrates once again how large the error rate can be in common forensic science techniques that most people consider reliable.