If you were stopped by police in Mesa and asked to perform field sobriety tests, you may already be facing serious legal exposure. Many people assume these tests are only used in alcohol DUI cases. In reality, officers throughout Mesa and Maricopa County frequently use field sobriety tests during drug investigations, including marijuana, prescription medication, and other controlled substances.
After a Mesa stop, identify whether the allegation is impaired driving, a drug-possession offense, or both. Roadside performance, a toxicology result and evidence of knowing possession answer different questions. Preserve the complete recordings and test records so counsel can compare each item with the actual charge.
What Are Field Sobriety Tests?
Field sobriety tests (FSTs) are roadside exercises used by law enforcement to determine whether a driver may be impaired. In Mesa, officers are trained to administer standardized tests developed by the National Highway Traffic Safety Administration (NHTSA), including:
- Horizontal Gaze Nystagmus (HGN) – Following a pen or light with your eyes
- Walk-and-Turn – Taking heel-to-toe steps along a straight line
- One-Leg Stand – Standing on one foot while counting
Review the officer’s instructions, recorded observations and testing conditions rather than treat the label “failed” as a complete explanation. NHTSA describes field testing and drug-recognition evaluation as parts of an impaired-driving investigation, with laboratory testing separately used for drug screening and confirmation.
When drugs are suspected, officers may request a Drug Recognition Expert evaluation. NHTSA describes a 12-step protocol addressing impairment, possible medical causes and likely drug categories. Request the actual evaluation and supporting records; the evaluator’s conclusion is not a substitute for reviewing its basis.
Can You Be Arrested for Drugs Based on Field Sobriety Tests Alone?
An arrest still requires its legal basis. Field-test observations may be part of the investigation, but they do not by themselves establish every element of every drug-related offense. Separate the impaired-driving allegation from any claimed possession or sale.
Compare the distinct provisions and limitations in Arizona Revised Statutes § 28-1381:
- Drive or be in actual physical control while impaired to the slightest degree by alcohol, drugs or the other substances specified in § 28-1381(A)(1)
- The drug-or-metabolite provision in § 28-1381(A)(3), subject to applicable limitations, including the prescribed-use rule in subsection D and the marijuana rule in § 36-2852(B)
- Lawful authorization to use a drug is not a defense to impairment under § 28-1381(A)(1); the prescribed-use limitation in subsection D applies specifically to A(3)
Unlike alcohol DUIs, Arizona does not require proof of a specific legal limit for most drugs. Prosecutors often rely on:
- Officer observations
- Field sobriety test performance
- Statements made during the stop
- Blood test results
However, poor performance on field sobriety tests does not automatically mean impairment. Fatigue, anxiety, medical conditions, uneven pavement, and even flashing patrol lights can affect results.
How Drug Arrests Happen in Mesa
Mesa police may initiate a stop for:
- Speeding or traffic violations
- Equipment issues such as broken taillights
- Suspicion of reckless driving
- Reports of erratic driving
From there, an officer may claim to observe:
- Red or watery eyes
- Slow speech
- Delayed responses
- Odor of marijuana
This often leads to roadside testing and potentially a blood draw.
After refusal of a chemical test under § 28-1321, testing may proceed under a search warrant or the statute’s specified exception. Refusal can also have separate licensing consequences. Preserve the request, advisement, warrant and collection records; do not assume a warrant or test is automatic or valid simply because it was obtained quickly.
Common Drug Charges Associated with Field Sobriety Stops
A roadside investigation may raise separate DUI and possession questions. For a dangerous-drug possession allegation, § 13-3407(A)(1) requires knowing possession or use; poor roadside performance does not replace review of the charged substance and conduct. Counsel should also examine the independent legal basis for any vehicle search.
Drug Possession – A.R.S. § 13-3407
Possession of a dangerous drug can be charged as a felony, even for small amounts.
Possession for Sale or Transportation for Sale
If officers believe the quantity or packaging suggests intent to sell, charges escalate dramatically.
Drug Paraphernalia – A.R.S. § 13-3415
Pipes, baggies, scales, or other items can lead to separate charges.
If you’re facing these accusations, you need an experienced drug crimes defense attorney who understands both DUI law and felony drug statutes.
What Happens After a Felony Drug Arrest in Arizona?
Many people search: What happens after a felony arrest in Arizona?
Here’s a simplified overview:
- Arrest and Booking – You are taken into custody and processed.
- Initial Appearance – A judge sets release conditions.
- Charging Decision – The prosecutor files formal charges.
- Pretrial Proceedings – Motions, evidence review, negotiations.
- Trial or Resolution – The case is dismissed, reduced, or goes to trial.
The consequences depend on the actual conviction. Section 28-1381 classifies its offenses as Class 1 misdemeanors; a separate felony drug allegation or aggravated-DUI statute requires its own analysis. Depending on the charges and applicable provisions, consequences may include:
- Jail or prison time
- Heavy fines
- Mandatory classes or treatment
- Driver’s license suspension
- Felony record
Penalties increase significantly if there are prior convictions or aggravating factors.
Defenses to Field Sobriety-Based Drug Arrests
An aggressive felony defense attorney will analyze every aspect of the stop, including:
- Was the traffic stop lawful?
- Were field sobriety tests administered correctly?
- Was there probable cause for arrest?
- Was the blood draw legally obtained?
- Were testing procedures properly followed?
Challenging procedure errors, improper searches, or unreliable testing can significantly weaken the prosecution’s case.
Why Early Legal Representation Matters
The hours and days after an arrest are critical.
A strategic criminal defense attorney Arizona residents rely on can:
- Intervene before formal charges are filed
- Preserve surveillance or bodycam footage
- Challenge improper searches
- Protect you from making damaging statements
- Develop a proactive defense strategy
Waiting can mean lost evidence and fewer options.
FAQs About Field Sobriety Tests and Drug Arrests in Mesa
Are field sobriety tests mandatory in Arizona?
No. You are not legally required to perform roadside field sobriety tests. However, refusing may still lead to arrest if the officer believes probable cause exists.
How are drug charges prosecuted in Arizona?
For an impaired-driving charge, compare the observations, field-test record, any DRE evaluation and toxicology with the relevant § 28-1381 allegation. For a separate possession charge, review the substance identification and evidence of knowing possession or use. A drug finding does not answer every impairment or possession question.
Can I be charged even if marijuana is legal in Arizona?
Driving while impaired remains prohibited. Under § 36-2852(B), marijuana components or metabolites support an A(3) violation only when the person is also impaired to the slightest degree. Review the alleged impairment separately from the laboratory’s detection result.
What if prescription medication caused the impairment?
Using medication as prescribed is not a defense to impairment under § 28-1381(A)(1). Section 28-1381(D) separately protects prescribed use from the drug-or-metabolite offense in A(3). Identify the actual subsection and preserve the prescription and test records for counsel.
Facing Drug or DUI Charges in Mesa? Guardian Law Group Is Ready to Defend You.
Drug-related DUI arrests can quickly escalate into serious felony charges. Whether you are under investigation or have already been charged, you need a results-driven, aggressive defense strategy.
Guardian Law Group represents clients facing criminal allegations, including drug offenses and related serious felony matters throughout Mesa, Phoenix, Scottsdale and Maricopa County.
For a Mesa consultation, bring the citation or complaint, complete available recordings, field-test and DRE records, laboratory report and any blood-test or licensing paperwork. Identify which facts allegedly support each charge. Guardian Law Group’s criminal defense team can review the documents and discuss the next step.
Call Guardian Law Group today at (602) 888-8020 for a confidential consultation.