I agree. The responsibility should be that of the defender, prosecuter, and judge to verify additional chemical tests prior to a plea or trial. The state prosecution should be required to back up any substance tests in order to press charges.

This way, the police can still do their job (although a certifiable training should be required and regulated for the field tests), while having an AGILE turnaround on immediate test verification analysis - which should be done by a court laboratory technician within days of initial arrest.