How to Challenge DataMaster Breathalyzer Results in Your DUI Case

You can challenge DataMaster breathalyzer results in a South Carolina DUI case, and drivers do it successfully. In South Carolina, breath testing runs on the DataMaster DMT, and its reading is only allowed into evidence if the police followed strict rules for how the test was given and recorded. When officers cut corners on the 20-minute observation period, the video recording, the machine’s calibration, or the operator’s certification, that breath result can be weakened or thrown out.

If you blew over the limit, do not assume the case is lost. Below are the exact points a Rock Hill DUI defense lawyer looks at to challenge a DataMaster breath test.

What Is the DataMaster DMT and How Does It Work?

The DataMaster DMT is the breath-testing instrument used across South Carolina. It sits at the police station or breath test site, not in the patrol car, and it measures the alcohol concentration in a breath sample. The machine is made by Intoximeters, Inc., and state law under Section 56-5-2934 gives you the right to obtain the software program behind it.

The test only measures alcohol. That matters because a reading is only as reliable as the procedure around it. If the process was flawed, the number on the ticket does not mean what the prosecutor says it means.

What Rules Must Police Follow for a Valid Breath Test?

South Carolina’s implied consent law at Section 56-5-2950 and the state’s regulations set out procedures that must be met before a breath result is admissible. Key requirements include:

• You must be told you have the right to refuse the test
• The breath test should be given within two hours of the arrest
• A 20-minute observation period must happen first, during which the operator watches to make sure you do not burp, vomit, or put anything in your mouth
• A simulator test must be run, and its reading must fall between 0.076 and 0.084
• The operator must be trained and certified on the machine
• The DataMaster must be properly maintained and calibrated
• You have the right to an independent test by a qualified person of your choosing, at your own cost

Miss one of these, and there may be a real basis to suppress the result.

Why the 20-Minute Observation Period Matters

The observation period exists for one reason: to rule out “mouth alcohol.” Alcohol trapped in the mouth from a burp, acid reflux, dental work, or chewing tobacco can spike a reading far above your true blood alcohol level. If the operator was filling out paperwork, left the room, or never actually checked your mouth before starting, the observation period may not hold up. On the video, this is often visible, or its absence is.

How the Breath Test Video Can Help Your Defense

South Carolina requires the whole event to be recorded. Under Section 56-5-2953, a person charged with DUI must have their conduct video recorded at both the incident site and the breath test site. The breath site video must show:

• The entire breath test procedure
• The 20-minute observation period
• You being told you are being recorded and that you can refuse
• The operator’s actions during the test

The video is powerful because it either proves the rules were followed or shows they were not. You can download your own breath site video directly from the SLED implied consent portal using the subject ID and password printed on your test form.

There is a catch. A missing video is not automatically a dismissal. The officer can submit a sworn affidavit that the equipment was inoperable and that reasonable efforts were made to keep it working. So the fight is often about whether that excuse is legitimate, not just whether a video exists.

How to Get the Machine’s Maintenance and Calibration Records

The DataMaster is a machine, and machines fail. To test its reliability, your attorney files a discovery request under Rule 5 of the South Carolina Rules of Criminal Procedure and requests records held by SLED, including:

• Calibration and simulator logs
• Maintenance and repair histories
• The breath site video

Under Section 56-5-2954, you have the right to breath-test maintenance records showing malfunctions and repairs. A device that failed calibration, needed repairs near your arrest date, or was overdue for maintenance gives your lawyer a concrete reason to question the reading.

What Happens If the Breath Result Is Suppressed?

If you were charged with driving with an unlawful alcohol concentration (DUAC) under Section 56-5-2933, the only real issue is your breath number. Knock out the DataMaster result, and the state may have no evidence you were at or above 0.08, which can lead to a dismissal.

Even in a standard DUI, weakening the breath test forces the prosecutor to prove impairment through the video and field tests alone, which is a much harder case.

Frequently Asked Questions

Can I refuse the DataMaster test in South Carolina?

Yes, but refusal carries its own penalty, including at least a six-month license suspension for a first refusal. Refusal can also be used against you, so the decision has real consequences either way.

Does a low or zero breath reading mean my case is dismissed?

Not necessarily. The state can still pursue a DUI based on impairment from drugs or a combination of substances, since the DataMaster only detects alcohol.

How long do I have to challenge my license suspension?

You have 30 days from the notice of suspension to request a contested case hearing with the Office of Motor Vehicle Hearings. Missing that window forfeits the challenge.

Do I need a lawyer to request the breath test records?

You can request some records yourself, but a formal Rule 5 discovery request and the technical review of calibration logs are where an attorney makes the difference.

Your Next Move After a DUI Breath Test

A DataMaster reading is evidence, not a verdict. The observation period, the video, the calibration records, and the operator’s certification all have to hold up, and often they do not.

At Okoye Law, our Rock Hill DUI defense team pulls the records, reviews the video frame by frame, and fights to keep bad breath evidence out. Schedule a consultation to get started.