Will Legalized Marijuana Create Problems Enforcing Pennsylvania Drug DUI Law?


Everyone knows that it is illegal to drive under the influence of alcohol if a person’s blood alcohol level is above the legal limit. With alcohol, a person is “under the influence” or affected by the alcohol as long as it is present in the  body. A person can also be charged with a drug-DUI for having drugs or drug by-products, called metabolites, above a specified limit in the person’s blood. With drugs, they often remain in a person’s body well after the effects of the drugs have worn off. The body is able to break down and rid itself of alcohol within hours, but the body is not able to rid itself of evidence of drugs as quickly. Therefore, a person may test positive for the presence of marijuana or THC in the blood weeks after the person actually ingested and was impaired by the drug. Again, it must be emphasized that under “per se” drug-DUI laws, a person can be convicted of driving under the influence even if not impaired as long as there are drug metabolites in the person’s system.

Future Constitutional Challenges to Marijuana Drug-DUI Charges

In the past, the constitutionality of the per se Pennsylvania drug-DUI charges was challenged. Pennsylvania courts upheld the law and found that it did not violate a person’s rights because the person did not have a right to have illegal substances in his or her body. Now, with many states making marijuana use legal, some people do lawfully have marijuana or THC in their system, so the rationale in upholding the per se drug-DUI law has now been undermined. I expect that challenges to the constitutionality of the drug-DUI law with regard to the prosecution of marijuana use may soon be challenged. The challenge would be limited to marijuana charges as other drugs such as cocaine, heroin, and methamphetamine remain illegal across the country.

It must also be noted that the challenge would only be made to the per se drug-DUI charges and not charges that punish a person for driving while impaired by  drugs. While a person may lawfully ingest marijuana in some states, they would still be prohibited from driving in Pennsylvania while they were impaired by the use of the drugs. Simply stated, the challenge would neither legalize marijuana use in Pennsylvania nor allow people to drive while under the influence of marijuana. It would simply allow a person to have non-active marijuana in their blood while driving in Pennsylvania.

In Pennsylvania, DUI charges are serious offenses, and a conviction results in the imposition of mandatory minimum sentences that often include jail time, hefty fines, and license suspensions. If you have been charged with any criminal offense, you should contact an experienced defense attorney such as State College driving under the influence lawyer Jason S. Dunkle.