DUI Per Se is based upon a “reading” or result from a DUI blood test, breath test, or urine test indicating that you had consumed enough alcohol to put you at or above the state’s legal blood alcohol content BAC limit. For example, a driver under age 21 stopped in Georgia is allowed up to a 0.02 breathalyzer reading, whereas a driver in Georgia who is age 21 or more (who is not operating a commercial motor vehicle) is allowed to have up to a 0.08 breathalyzer reading. An adult driver stopped in North Carolina is allowed the same 0.08 result, but drivers under age 21 are held to a 0.00 reading. Reduced to basic terms, most misdemeanor DUI offenses consist of four basic elements: (a) the prohibited vehicular activity – the operation or other use, (b) of a vehicle (usually a “motor vehicle”), (c) in a location identified as being covered by that state’s laws, (d) while influenced by the consumption of an intoxicant.

Typically, these four elements must be proven beyond a reasonable doubt to convict a person of any DUI-DWI offense except a DUI per se offense. In a per se DUI offense the prosecution does not have to prove that the consumption of the intoxicant affected the defendant’s ability to operate a vehicle. A DUI-DWI per se case merely requires that the prosecution be able to put the test result into evidence and to convince the judge or jury that the result is reliable and trustworthy.

Thus, under a per se DUI statute the prosecution does not have to prove that the defendant was under the influence of the alcohol consumed. Impairment is not a required “element” of a per se alcohol DUI-DWI offense. No expert witness is needed for the prosecution to correlate (“match up”) the alleged blood (or breath) alcohol concentration to any degree of impairment, since a blood alcohol concentration at or above the level set forth in the statute is itself sufficient for conviction, regardless of impairment. Under a “per se” statute intoxication, in the traditional sense, is not a “guilt or innocence” issue. The issue of guilt or innocence depends upon whether the jury believes that the defendant had a prohibited blood alcohol concentration in his or her system at the time of driving (or, in some states, within 2, 3 or 4 hours after driving ended), from alcohol consumed before or during driving. To win your case against a per se alcohol DUI reading at or over the applicable legal limit, a highly-trained expert witness will be required in almost all instances.

In some states, it should be noted that the “per se” statutes proscribe (i.e., makes illegal) operating or driving with prohibited levels of alcohol in a person’s blood, breath or urine. However, due to “pooling” issues, urine testing for alcohol content is notoriously unreliable to provide accurate “quantitative” results. A skilled DUI-DWI defense attorney and a qualified expert witness can devastate the reliability of such breath test results.

Under a “per se” statute, as under any DUI-DWI statute, it must be proven beyond a reasonable doubt that the defendant “drove” or “operated” “a vehicle” in “a prohibited area,” as previously discussed in this section. However, instead of proving that the defendant was intoxicated or under the influence of alcohol at the time of the alleged offense, the prosecution need only prove beyond a reasonable doubt that the defendant’s alcohol concentration (from a test of blood, breath or urine) was at or above the prohibited level at the time of the driving. Some states have removed from their laws any “burden” on the State to prove what your BAC actually was WHEN driving, so long as your test was conducted within the statutory “window” set by your state’s laws (typically 2 or 3 hours after the driving ended).

The constitutionality of “DUI per se” statutes has been consistently upheld by the courts despite attacks on a number of grounds. “Per se” statutes have been most frequently challenged on the ground that they violate due process of law by creating an unconstitutional irrebuttable presumption of intoxication. The courts have rejected this assertion by holding that “per se” statutes create a new crime and not a presumption of intoxication.

Several constitutional challenges have been taken regarding the “irrebutable” presumption set forth in statutes wherein a breath or blood test taken within 2, 3 or even 4 hours (depending on your state’s laws) after you stopped driving would be “good evidence” under the statute. In other words, if the number obtained was “taken” from a test that was administered to you within the statutory time limit after the traffic stop, that was a violation of the per se DUI law. Such legal rulings ignore the “science” behind alcohol absorption and elimination, and allow conviction of innocent people who can PROVE that their alcohol level was still rising when stopped by the police shortly after their last drink.

Because alcohol is absorbed over a lengthy period after being consumed, and then eliminated over an even longer period, the attack is based on the fact that proof of consumption whereby the person’s alcohol level was still rising when stopped, and arguably HIGHER when tested (possibly 45 minutes to an hour later), this violated due process rights. Several states have ruled that the State has the burden to prove the “number” at the time of driving, and without such proof, the defendant wins on this issue. These states have upheld the spirit of due process over abdicating the political pressure and public opinion by “legislating” science to obtain convictions of people who may NOT have had the prohibited amount of alcohol in their systems when driving.

It has been held that in protecting the safety of its citizens a state legislature may determine that a driver with a blood alcohol concentration of 0.08% or more constitutes a serious and immediate threat to the public safety, and that the passage of a “per se” statute is a reasonable means of protecting the public safety. The constitutionality of such breath alcohol “per se” statutes has also been upheld.

The constitutionality of “DUI per se” statutes has also been challenged on a “void for vagueness” attack. Defendants have alleged that because they have no way of knowing when their blood alcohol concentration reaches the prohibited level, “per se” statutes fail to give adequate notice of the forbidden conduct and are therefore unconstitutionally vague. The courts have rejected this argument, ruling that the consumption of alcohol should put a person of ordinary intelligence on notice that he or she is in jeopardy of violating the statute and that any person who drives after drinking should reasonably be aware of the possibility of violating the statute.

It has been held that the enforcement of a “per se” statute is not an unreasonable or unconstitutional exercise of police power. It has also been held that a “per se” statute does not violate the equal protection clause of the Constitution. Finally, the use of an implied consent law in conjunction with a “per se” statute has been upheld against a claim that the conclusiveness of the evidence of blood alcohol concentration violates a defendant’s privilege against self-incrimination.

Chemical tests can play an important role in the prosecution of most DUI-DWI offenses. However, because of the nature of a “per se” offense, the prosecution must prove the accuracy and reliability of the chemical test in “per se” cases more than in other types of DUI-DWI cases. Because a chemical test result is normally the only significant evidence required to provide proof of a person’s guilt in a “per se” case, some fair-minded courts have held that a higher degree of testing accuracy should be required in a “per se” case than in other types of DUI-DWI cases.

In most states, where a test result at or above the 0.08% limit has been obtained by police, a “DUI per se” offense will be accused (charged) as a separate and distinct “count” (the way that the state claims that the DUI-DWI law has been violated) from the traditional or common law offense of “driving while under the influence” or “driving while intoxicated.” More often than not, however, both offenses are based on the same conduct by the defendant, and it is common in many states for a defendant to be charged with both offenses (in alternative “counts”) in the same complaint or information. Once again, the defense must bring to court an expert witness who can explain to the jury or judge why the alcohol test result is unreliable or not worthy of belief.

Multiple convictions resulting from the same conduct are not permitted in many states and in the states where multiple convictions are allowed, multiple punishments (for a single act of drunk driving) are not permitted. In a few states a “per se DUI” offense is treated as a lesser included offense of driving while under the influence of alcohol or of driving while intoxicated, and multiple convictions are thereby precluded.