When should a urine test be requested after a breath test?

Requesting a urine test after a breath test is appropriate when there is probable cause to believe that the driver may be impaired by substances other than alcohol. Breath tests are primarily designed to measure blood alcohol concentration (BAC), but they do not provide information about the presence or level of other substances, such as drugs.

If a law enforcement officer observes indicators of impairment that suggest the influence of narcotics or other non-alcoholic substances, a urine test can help confirm this suspicion. The ability to test for a wider range of substances through urine analysis allows officers to gather more comprehensive evidence of impairment beyond what a breath test can detect.

In cases where the breath test yields a low BAC result, is inconclusive, or if it wasn't administered at all, there may not be a sufficient basis to request a urine test based solely on those factors without additional evidence pointing to impairment from other substances. Therefore, establishing probable cause related to other forms of substance impairment is a crucial factor in deciding to conduct a urine test.