In Maryland, there are two different types of alcohol driving offenses.
The first is the 21902A statute, known as a DUI (driving under the influence of alcohol). Within that one statue, there are several variations:
A DUI per se, happens when you get pulled over and fail to pass the test(s). When this happens, you go back to the barracks to give a breath alcohol concentration test or submit a breath alcohol concentration sample, yielding a result of over the legal limit: 0.08. This is what’s called per se, because the test stands on its own, showing you were intoxicated to that level. That is the highest level DUI offense we have in Maryland. The penalty is a year in jail and a thousand dollar fine for the first offense.
The next is a general DUI, when you’ve been pulled over for driving erratically. In this case, you have failed the field sobriety tests miserably and potentially didn’t give a breath sample at the barracks. The police can take the totality of these circumstances and present them to the court. The court may find that you were intoxicated enough to meet the higher level of a 21902A DUI.
The second is the general 21902B, commonly known as a DWI (driving while impaired). This is often more difficult for the state to prove and typically carries less penalty: 60 days in jail and a $500 fine.
With a DWI, you were mostly likely pulled over, did marginally on the roadside field sobriety test, and did not submit a breath sample at the barracks after being taken into custody. When the prosecutor presents their case, they rely strictly on the roadside test to show that you were impaired to some degree. It’s not a high burden to meet, but the state can prove their case beyond reasonable doubt using those words, sight tests, police officer’s statements, experience, testing credentials, and such.