Per se law refers to the blood alcohol concentration (BAC) level of an individual at the time of driving being above the legally permissible limit (0.08%). This alone is viewed as enough proof that the individual is guilty of drunk driving. The prosecutor(s) doesn't need any additional proof of impairment to obtain a conviction against the individual.
Per se is a Latin word that means "by itself." Throughout all of the United States, driving a vehicle with a blood alcohol concentration (BAC) level of 0.08% is considered a crime. It is referred to as driving under the influence (DUI; it is also known as DWI). The per se law states that if the tests performed on an individual suspected of drunk driving, by a law enforcement officer, establish that the individual had a BAC level of 0.08% or higher, there is sufficient proof to establish the individual as guilty of DUI. According to per se law, the prosecutor(s) doesn't need to submit any additional proof of impairment to get a conviction against an individual.