PBT Evidence in Oklahoma DUI Cases: What Courts Really Allow
You may have blown into a small handheld breath machine on the side of the road. That preliminary breath test (PBT), sometimes called a portable breath test, can feel like the whole case against you. However, Oklahoma law treats PBT evidence very differently from the big evidential breath machines at the station. If prosecutors try to use PBT evidence at your trial, you have powerful ways to fight back.
The key case on this issue is State v. Cardenas-Moreno. That decision explains when PBT results might come in and when they should stay out. Oklahoma administrative rules add another important layer because they control which devices count as approved “alcohol screening devices” and how officers must operate and maintain them.
Accused of an Oklahoma DUI Based on a PBT?
If you’ve been accused of DUI, aggravated DUI, DWI, or APC in Oklahoma and a PBT is part of the evidence, reach out for a free consultation. You can call us at 405-633-3420 or use our secure online form.
Oklahoma DUI, APC, Aggravated DUI, and DWI Charges That Involve PBT Evidence
What Is a Preliminary Breath Test in Oklahoma?
A PBT is a small handheld device, sometimes called a portable breath test, that measures alcohol in your breath at the roadside. Officers usually bring it out after field sobriety tests. Unlike station breath machines, these devices are designed as screening tools. They help officers decide whether to arrest you, not to prove a precise BAC at trial.
Oklahoma rules call these tools “alcohol screening devices.” They must be approved under lists published by the National Highway Traffic Safety Administration. Those rules appear in the Oklahoma Administrative Code at OAC 40:55-1-1 and related sections. Later sections set out how officers must operate and calibrate the devices.
How the Oklahoma Administrative Code Affects PBT Admissibility
The Oklahoma Administrative Code doesn’t directly say when judges must admit PBT results. However, it sets the technical standards that shape reliability. That reliability question is crucial under Cardenas-Moreno. When you challenge a PBT, you’re often arguing that officers didn’t follow these rules or that the device itself doesn’t meet them.
- Approved devices – OAC 40:55-1-1: Only devices on specific NHTSA “Conforming Products Lists” or that meet federal model specifications count as approved alcohol screening devices for law enforcement use. An unlisted device is a major reliability issue.
- Operating procedure – OAC 40:55-1-2: Officers must use these devices as presumptive preliminary breath tests, follow the manufacturer’s directions, and watch you for at least 15 minutes prior to administering the test. During that time you can’t eat, drink, vomit, or smoke.
- Calibration and checks – OAC 40:55-1-3: Approved devices need an annual calibration check. The reading must fall within 0.005 g/210L of the reference value, or the device requires calibration. Missing records or out-of-tolerance results create powerful impeachment material.
When officers ignore these rules, the PBT becomes much easier to attack. You can argue the device wasn’t truly “approved,” the test wasn’t properly administered, or the results are simply too unreliable to go to a jury. Those arguments feed directly into motions to suppress and into objections during trial.
What NHTSA SFST Training Tells Officers About PBT Administration
PBTs in NHTSA’s Phase Three Pre-Arrest Screening
NHTSA’s Standardized Field Sobriety Testing (SFST) course (that attorney Frank Urbanic has attended) treats the PBT as part of Phase Three, the pre-arrest screening stage. During this phase, you’re usually not under arrest yet. Officers are taught to base the arrest decision on driving behavior, personal contact, and the three standardized field sobriety tests first. The PBT comes in after those steps as a way to confirm the chemical basis of the impairment they think they’re seeing.
PBT as a BAC Indicator, Not a “Drunk Meter”
The manual defines a preliminary breath test as a pre-arrest breath test used to get an indication of your blood alcohol concentration. It stresses that the basic purpose is to connect alcohol with the observed clues, not to measure how “drunk” you are. Impairment varies widely from person to person at the same BAC. Because of that, NHTSA tells officers to treat the PBT as one more piece in the probable cause puzzle, not the star of the show.
Why a PBT Alone Shouldn’t Justify a DWI Arrest
NHTSA also warns officers that the PBT result shouldn’t, whenever possible, be the sole basis for a DWI arrest. Instead, the PBT should corroborate what the officer already saw with the SFSTs and other observations. The manual explains that a high BAC on the PBT without strong field sobriety evidence is a red flag. Likewise, a low PBT number with obvious impairment suggests they need to look for drugs or a medical condition instead of assuming alcohol explains everything.
Real-World Factors That Can Skew a PBT Result
The training materials spend time on the limits of PBT accuracy. Officers are told that residual mouth alcohol can inflate a reading, especially if you’ve recently used alcohol-based products or taken a drink. They’re taught to wait at least 15 to 20 minutes and to keep anything out of your mouth before the test. They’re also warned about breath contaminants like certain solvents or heavy cigarette smoke, breath sample cooling if the sample sits too long, and shallow breaths that don’t capture deep lung air. When they follow those rules, the device is “reasonably accurate,” but only when used the way NHTSA describes.
Why NHTSA Puts SFSTs Before the Preliminary Breath Test
NHTSA’s SFST training also makes it clear that officers aren’t supposed to jump straight to the preliminary breath test at the beginning of the contact. They’re taught to use the PBT only after they’ve already observed your driving, spoken with you, and administered the standardized field sobriety tests. That order matters because the arrest decision is supposed to rest on clear signs of impairment, not on a single roadside gadget with known limits and potential error sources. By putting the SFSTs first and the PBT second, NHTSA tries to ensure officers build probable cause on what they actually see and hear, then use the PBT only to confirm that alcohol is likely driving the clues they observed.
State Law Limits on Using PBT Results in Court
Finally, NHTSA reminds officers that each state sets the evidentiary limits on PBT use. The SFST manual specifically tells them to consult their state PBT law, their supervisor, or local prosecutors about whether and how PBT results can be used in court. That point matters in Oklahoma because Cardenas-Moreno and the administrative code together restrict how far prosecutors can push a roadside number in front of a jury.
What Can Affect the Reliability of a Preliminary Breath Test Result?
A preliminary breath test can look scientific, but plenty of real-world factors can throw off the number. Residual mouth alcohol from recent drinks, burping, vomiting, or using alcohol-based products can spike a reading well above your true breath alcohol level. Environmental conditions like very cold or hot air, heavy cigarette smoke, or chemical fumes can also interfere with the device. Even how you blow matters; a shallow or “short” breath sample may not capture deep lung air, while an extra-forceful blow can confuse some sensors. On top of that, calibration problems, low batteries, and poor officer training can all drag the PBT outside the accuracy range NHTSA expects. When you pull those issues together, you can see why Oklahoma law treats the PBT as a limited screening tool rather than rock-solid proof of your actual BAC.
State v. Cardenas-Moreno: What the Oklahoma Court of Criminal Appeals Decided
In State v. Cardenas-Moreno, the trial judge ruled that PBT tests were never admissible in Oklahoma. The Court of Criminal Appeals reversed that blanket ruling. Instead, the court held that PBTs can come into evidence when they’re used like a field sobriety test to estimate impairment and when the State doesn’t offer a specific number as a BAC.
The court relied on 47 O.S. § 11-902(N), which allows “all field sobriety tests” to be admitted in DUI trials. However, the opinion stressed that admissibility still depends on reliability and on the specific use of the PBT. A concurrence also noted that PBTs are scientific devices and may require a reliability foundation similar to other expert evidence.
Because of that decision, you no longer win by arguing that PBTs are categorically barred. Instead, you win by showing that the State is using the PBT in the wrong way or without a solid foundation. The details of how officers used the device now matter more than ever.
Where the Lines are After Cardenas-Moreno
1. When the State Tries to Introduce a PBT Number
Prosecutors sometimes want to put a specific roadside number in front of the jury. That number might look like “0.13 on the PBT.” However, Cardenas-Moreno carefully distinguished that situation. The court approved PBT evidence only when the State didn’t seek to admit a specific numeric concentration.
So your lawyer can argue that using a PBT number violates the spirit of the decision and risks unfair prejudice. The numeric reading invites jurors to treat the PBT like a certified evidential test, even though it isn’t. You can object under relevancy rules, unfair prejudice, and reliability rules, and you can point to the administrative code when the device or procedure doesn’t meet those standards.
In practice, many judges are reluctant to admit a PBT number at trial. They often agree that any BAC figure should come only from properly certified evidential testing. You should still attack the number through a motion to suppress or motion in limine so the fight happens before a jury ever hears it.
If the preliminary breath test number shows on a video the prosecutor wants to play for the jury, you’ve got a new problem and a new opportunity. The State might claim they’re only using the video to show your behavior, but that glowing PBT number invites jurors to treat it like certified BAC proof. You can ask the judge to blur or crop the number, mute any audio where it’s read out, or keep the video out entirely. That way, the jury sees what matters—your driving, your speech, your balance—without being subconsciously influenced by a roadside gadget.
2. When the State Offers a “Pass/Fail” or “Positive” Result
Prosecutors sometimes try to treat the PBT like another field sobriety test. They’ll say you “failed” or had a “positive” result, without giving a number. This is the exact posture that Cardenas-Moreno considered acceptable if the State lays a proper foundation and uses the result only to support a general impairment claim.
Even in that posture, you can still challenge reliability. You can demand proof that the device appears on the approved list, that officers followed the 15-minute observation rule, and that calibration checks were current. If the State can’t prove those points, you can argue that the PBT fails the reliability standards that the court required.
Your lawyer can also argue that the “pass/fail” label still hides an undisclosed number and misleads the jury. In some cases, judges limit officers to describing the device as “one of several tools” that contributed to probable cause rather than as strong proof that you were actually impaired.
3. When the Officer Gives Opinion Testimony Based on the PBT
Sometimes the State doesn’t introduce the PBT result directly. Instead, the officer testifies that the PBT “confirmed” impairment or made them “more confident” that you were drunk. That testimony still relies on the PBT and should raise the same foundational issues.
Your attorney can argue that any opinion “based on” the PBT requires proof that the device and test were reliable. Without that proof, the opinion rests on shaky ground. In more complex cases, you can demand a scientific reliability hearing. There, the State must show that the technology and the way officers used it meet Oklahoma’s standards for expert evidence.
Courts may still allow officers to describe the sequence of events during the stop. However, a careful objection can prevent them from leaning too heavily on the PBT as the main reason to believe you were impaired. That distinction can make a real difference at trial.
Using Motions to Suppress or Motions in Limine to Keep PBT Evidence Out
The fight over PBT evidence usually starts before trial. A motion to suppress or motion in limine asks the judge to keep the PBT out or to limit how the State can use it. When you challenge the PBT early, you can narrow what the jury hears and force the State to expose weaknesses in the investigation.
- Targeted discovery: You can request device serial numbers, maintenance logs, calibration certificates, and training records. Any gaps support a reliability challenge.
- Administrative noncompliance: If the device isn’t on the approved list or calibration checks fall outside the allowed range, you can argue that the screening device doesn’t meet Oklahoma’s own standards.
- Probable cause arguments: When officers rely too heavily on a flawed PBT, you can argue that the arrest lacked probable cause. That challenge can affect later evidential tests as well.
- Limits on trial use: Even if the judge allows the PBT, you can ask for limits. For example, you can seek an order barring any numeric reading or restricting the device to probable-cause testimony only.
A well-prepared motion hearing gives your attorney a chance to cross-examine the officer before trial. That testimony can expose shaky procedures, missing paperwork, or confusion about the device. Later, those same weaknesses help you during plea negotiations or at trial.
Key Terms in Oklahoma Preliminary Breath Test Cases
Understanding a few core terms makes it easier to follow what’s happening in your case. These concepts also line up with how courts and statutes talk about PBT evidence in Oklahoma.
- Preliminary Breath Test (PBT)
- A small handheld “alcohol screening device” used at the roadside, sometimes called a portable breath test. It gives a quick estimate of how much alcohol is in your breath and helps officers decide whether to arrest you.
- Alcohol Screening Device
- The term Oklahoma uses in its administrative code for approved PBT-type devices. To qualify, the device must appear on NHTSA conforming lists and meet specific calibration and operating rules.
- Evidential Breath Test
- A breath test performed on a larger certified machine, usually at a station or jail. Courts treat these tests as primary evidence of BAC when proper procedures are followed.
- Field Sobriety Test
- Roadside exercises like the walk-and-turn, one-leg stand, and eye tests. Under 47 O.S. § 11-902(N), the State can offer these tests, including certain PBT uses, to show impairment.
- Aggravated DUI
- A DUI offense where your BAC is 0.15 or higher under 47 O.S. § 11-902(D). It carries enhanced penalties and can be a felony under current Oklahoma law.
- Actual Physical Control (APC)
- A charge under 47 O.S. § 11-902 that applies when you’re in a position to operate a vehicle while impaired, even if you never actually drive.
- Driving While Impaired (DWI)
- An offense under 47 O.S. § 761 that addresses driving with a BAC between 0.06 and 0.07 when alcohol affects your ability to operate a vehicle.
FAQs About Preliminary Breath Tests in Oklahoma
Are preliminary breath tests admissible in Oklahoma DUI trials?
PBTs aren’t automatically admissible or automatically excluded in Oklahoma. After Cardenas-Moreno, judges may allow PBT evidence when the State uses it like a field sobriety test to estimate impairment and doesn’t introduce a specific number. However, you can still challenge reliability based on device approval, calibration, and how the officer ran the test.
Can Oklahoma prosecutors use my preliminary breath test number at trial?
Prosecutors often try, but you have strong arguments against it. The appellate court approved PBT evidence only when the State avoided using a numeric BAC. You can argue that the number belongs only in probable-cause discussions, not in front of the jury. Judges frequently treat the PBT number as too unreliable and too prejudicial to be admitted.
How does the Oklahoma administrative code affect preliminary breath test reliability?
The administrative code decides which devices count as approved alcohol screening devices and how they must be operated and calibrated. If the State can’t prove that your device was on the approved list or that officers followed the observation and calibration rules, you can argue that the PBT is unreliable. That unreliability supports motions to suppress and trial objections.
Can an officer in Oklahoma say I “failed” the preliminary breath test?
Officers often claim you “failed” or had a “positive” PBT. After Cardenas-Moreno, judges may allow that kind of testimony if the State treats the PBT like a field sobriety test and shows basic reliability. However, you can argue that the “fail” label hides an undisclosed number and misleads the jury, especially when the device or procedure doesn’t meet Oklahoma’s own rules.
Do you have to take a preliminary breath test in Oklahoma?
Oklahoma’s implied-consent laws focus on evidential breath or blood tests after an arrest, not on roadside screening devices. PBTs are usually voluntary, although officers may pressure you to blow. Refusing a PBT can still influence the officer’s decision to arrest you, but the legal consequences are very different from refusing an evidential test at the station.
PBT evidence sits in a gray area of Oklahoma DUI law. Courts no longer treat it as automatically inadmissible, yet they still demand reliability and proper use. When you understand how the statutes, administrative rules, NHTSA training, and Cardenas-Moreno fit together, you’re better positioned to protect your rights and challenge weak evidence built on a roadside gadget.
This page is for informational purposes only and is not legal advice. Every case is unique; consult an attorney about your specific situation. Page last updated [today’s date]. Consult the statutes listed above for the most up-to-date law.
