Tests Showed Justin Bieber Had Used Marijuana and Prescription Drugs. Was He DWI?

Police reports and lab results made public on the TMZ website show Bieber had chemicals in his urine which are metabolites of certain drugs / medications that can cause impairment in a driver.  Officers secured a specimen of urine from Bieber in order to attempt to determine if he was DWI on drugs other than alcohol.  The urine was collected after Bieber provided a breath test that indicated he was not intoxicated due to drinking alcohol.

Police tested the urine specimen for a limited number of drugs and medications.  The urine was tested at the forensic laboratory located at the University of Miami.


The urine was tested for certain chemicals associated with the use of marijuana.  According to the lab report, Bieber’s urine had a detectable amount of Delta 9 Carboxy-tetrahydrocanabinol (THC).  Delta 9 THC is a psychoactive drug that can cause impairment of faculties, but the substance detected in Bieber’s urine was a secondary metabolite that does not cause impairment.

Would Justin Bieber be guilty of DWI under Texas law?

The first problem with this avenue is the fact the drug was detected in urine rather than blood.  Urine contained in the bladder is post systemic.  The contents of the bladder offer some indication of what types of drugs  had been in person’s system at some point in time earlier that day or even in the days before.  Chemicals and metabolites in urine DO NOT offer evidence of whether a person has the normal use of mental or physical faculties at the time the urine is collected from the bladder.  The bladder is essentially a trash can of the body.  Marijuana metabolites can continue to appear in urine results for weeks after the last use.  Therefore, NO, a positive urine test does not suggest a person may be intoxicated on marijuana at the time the specimen os collected.


Alprazolam is the generic name for the brand name anti-anxiety medication called Xanax.  Xanax is a benzodiazepine that acts as a depressant drug on the nervous system, similarly to alcohol.  The test result did not specify what actual drug was detected in the testing.  Alprazolam has metabolites, some active and others not capable of affecting a person’s faculties.  This result would need to be more specific to be meaningful in determining intoxication.  Regardless of the drug though, the alprazolam result has the same problem as the marijuana- it was merely detected in urine- Bieber’s trash can.

Police Cannot Extrapolate Urine Results

Since urine contents are in a sense static and not part of the absorption and distribution system of the human body, urine contents do not offer a vantage point from which blood or brain concentrations can be determined.  Even when drugs or medications can be detected in blood, the practice of extrapolating the amounts to the time a person was driving is marginally scientific.

DWI in Texas?

Without much more evidence, the simple presence of drugs in Bieber’s urine do not begin to suggest he did not have perfect command of his faculties when he was driving.  The presence of these drugs / medication in his urine should not even be relevant in deciding whether he was impaired.  Texas does not have any per se intoxication offense with regard to drugs other than alcohol.  Therefore, even if these drugs had been detected in blood, and even in a quantified concentration, DWI could not be proven without proof that Bieber’s faculties were rendered outside of the normal range due to the taking of the drugs.