The Penalties for a Marijuana DUI in Washington State

Marijuana DUI Penalties in Tacoma, WA: What You Need to Know

Although recreational marijuana use is legal in Washington, it remains a serious criminal offense to drive while under the influence of marijuana. At Smith & White, our Tacoma DUI defense attorneys regularly defend clients charged with marijuana DUIs in Pierce County and surrounding areas. If you have been arrested for driving under the influence of THC, understanding the consequences and available defenses is critical.

Marijuana DUI Under Washington Law

Under RCW 46.61.502, it is illegal to drive a vehicle while under the influence of marijuana. You can be charged in two ways:

• Per Se DUI: If your blood test shows five or more nanograms of THC per milliliter of blood.
• Impairment-Based DUI: If law enforcement believes your ability to drive was appreciably affected by marijuana use, regardless of your THC level.

This distinction is important: the State does not need to prove both—just one.

Why the 5 Nanogram THC Standard is Misleading

Numerous peer-reviewed studies and government-backed research show that THC blood levels do not correlate directly with impairment. THC behaves differently than alcohol:

• It is fat-soluble, not water-soluble, so it remains in the body longer.
• Tolerance levels vary drastically between users.
• Methods of consumption (smoking vs. edibles) alter absorption and peak levels.

A frequent medical marijuana user might test over 5 ng/mL for days after last use—even when entirely sober. The 5 ng/mL standard is thus a legal shortcut, not a medical or scientific benchmark for actual impairment.

Nevertheless, Washington law applies this standard strictly. That means prosecutors can (and do) pursue DUI charges even when there is no evidence of bad driving or observable impairment.

How Police Investigate Marijuana DUIs in Pierce County

A marijuana DUI case often begins with a basic traffic stop. Once a Tacoma officer suspects marijuana consumption, the process may include:

• Standardized Field Sobriety Tests (SFSTs): These were developed for alcohol and are unreliable for cannabis detection.
• Drug Recognition Expert (DRE) Evaluation: A specially trained officer attempts to confirm drug impairment based on subjective observations.
• Blood Test: If you consent or if the officer obtains a warrant, your blood may be drawn to test THC levels.

Unfortunately, none of these methods definitively prove that a person was actually impaired while driving. At Smith & White, we challenge these assumptions in court.

Hypothetical Case: Misapplied DUI Charge

Sarah, a nurse in Tacoma, uses state-licensed medical marijuana to treat anxiety. One afternoon, she is pulled over for a cracked tail light. The officer smells cannabis in her car and claims her speech is slow. Sarah is arrested. She had not used marijuana that day, but a blood test reveals 6.1 ng/mL of THC. She is charged with DUI.

This case illustrates a real danger in Washington’s per se marijuana DUI statute: presence does not equal impairment. Our firm routinely defends clients in this situation and has successfully challenged both the science and the arrest procedures used.

Consequences of a Marijuana DUI Conviction

Marijuana DUIs are generally charged as gross misdemeanors, but certain factors can elevate the charge:

• Gross Misdemeanor: Up to 364 days in jail, a $5,000 fine, 90-day license suspension, and probation.
• Felony DUI (Class B): If you have three or more prior DUIs within 10 years, or if you’ve previously been convicted of vehicular assault or homicide under the influence.

Even a misdemeanor DUI can result in:

• Installation of an ignition interlock device (IID)
• Community service
• Substance use evaluation and treatment
• Permanent criminal record

A permanent criminal record can lead to long-term issues:

• Difficulty renting housing
• Trouble securing employment or professional licenses
• Obstacles in pursuing higher education
• Immigration consequences for non-citizens

Collateral Consequences: Immigration and Employment

A marijuana DUI conviction can impact more than just your record:

• Immigration Status: For lawful permanent residents or visa holders, a DUI may cause denial of reentry or green card renewal.
• Military Personnel: Marijuana DUIs can result in discharge or loss of security clearance.
• Healthcare, Teaching, and Other Licensed Fields: Your professional license may be suspended or revoked.
• Commercial Drivers (CDL Holders): Any DUI conviction can result in a one-year disqualification of your CDL, even for a first offense.

These consequences make experienced legal counsel essential.

Refusing a Blood Test: What You Should Know

Washington’s implied consent law (RCW 46.20.308) means that by driving on Washington roads, you agree to submit to a blood test when lawfully arrested for DUI. However:

• A warrant is usually required for a blood draw.
• Refusing a valid test can lead to a one-year license suspension and may be used against you in court.
• Unlawful or warrantless tests can be challenged and suppressed by your defense attorney.

Smith & White regularly identifies and challenges blood tests that do not meet constitutional standards.

Best Defense Strategies for Marijuana DUI Charges

Our Tacoma DUI attorneys build custom defense strategies depending on the facts of each case. Common defenses include:

• Lack of Probable Cause: If the initial traffic stop or arrest was unlawful, all evidence may be excluded.
• No Signs of Actual Impairment: Absence of poor driving, confusion, or slurred speech can be emphasized.
• Blood Test Challenges: Questioning the validity, delay, or contamination in testing.
• Unreliable Field Tests or DRE Opinion: Highlighting how subjective and flawed these tools are.

Our team has helped clients avoid jail time, reduce charges, and in some cases, get the case dismissed entirely.

Why You Should Act Quickly

If you were arrested for marijuana DUI in Pierce County, timing matters. You have only seven days to request a hearing with the Department of Licensing (DOL) to try to preserve your license. In addition, early legal intervention allows us to:

• Gather and preserve time-sensitive evidence (dashcam footage, witness statements)
• Negotiate with prosecutors
• Begin building your strongest defense

Contact Smith & White: Experienced Tacoma DUI Defense Lawyers

The penalties for a marijuana DUI in Washington State can be life-altering. But a charge is not a conviction. With over 27 years of experience in Tacoma courts, our attorneys know how to challenge flawed drug DUI charges and protect your future.

Facing DUI charges? Don’t navigate the system alone—reach out to our Tacoma office today. Call (253) 203-1645 or complete our online form for a confidential consultation.