A driver’s blood alcohol concentration (BAC) is a common source of evidence that is used to determine whether they were operating a vehicle under the influence of alcohol. Unlike subjective observations by law enforcement, BAC provides an objective measurement of impairment. If a driver’s BAC is above the legal threshold of .08%, they could be charged with a DWI. It’s important to understand what affects BAC — and how it can impact a DWI case.
What is the Impact of BAC in a DWI?
Blood alcohol concentration — commonly referred to as “blood alcohol content” or “BAC” — is the amount of alcohol in a person’s bloodstream. It is a measurement that reflects an individual’s level of intoxication and helps law enforcement determine whether they are too impaired to operate a motor vehicle. Specifically, a person’s BAC can be measured in three ways. This evidence can be gathered through breath testing, urine testing, or blood testing.
A driver’s BAC can serve as scientific evidence of impairment and can hold considerable weight in a DWI case. The BAC level of an individual who is pulled over for driving while intoxicated directly impacts the severity of the legal consequences they may face. Under New York law, the BAC limits for drivers are as follows:
- BAC of .04% — This is the legal BAC threshold for commercial drivers.
- BAC of .05% — Legal evidence of impairment to support a charge of Driving While Ability Impaired (DWAI).
- BAC of .08% — Evidence that a driver is legally intoxicated.
- BAC of .18% or more — When a person has a BAC at this level, it is considered an aggravated DWI.
Importantly, New York’s Zero Tolerance Law makes it illegal for an individual under the age of 21 to have any measurable amount of alcohol in their system.
What Affects a Driver’s BAC?
It’s always best for an individual to have a designated driver if they plan to consume alcohol. While the pace at which alcohol is consumed and the number of drinks a person has are the most significant factors that affect intoxication, there are several other factors that can affect a driver’s BAC level. These can include gender, weight, metabolism, dehydration, fatigue, medication, and how much the individual has had to eat.
The type of alcohol consumed does not directly influence a person’s BAC. However, the amount of a certain type of drink can. According to the NHSTA, a typical drink equals about half an ounce of alcohol. This is the same amount of alcohol found in one shot of distilled spirits, one 5-ounce glass of wine, or one 12-ounce beer.
What Defenses are Available for Driving with a BAC Above the Limit?
If you have been charged with driving while intoxicated, a good criminal defense attorney can evaluate your case and develop a defense strategy based on the facts. Depending on the circumstances, Constitutional violations or a police officer’s failure to adhere to proper procedures can lead to the evidence collected in the case being rendered inadmissible.
Notably, one of the most common challenges a defense attorney can raise against the prosecution’s evidence concerns the accuracy and reliability of a BAC test. Issues such as failure to calibrate, improper administration of the test, and underlying medical conditions can all affect the results. In addition, if the police officer was not properly trained to administer a breathalyzer test, the test may not be admissible as evidence.
Contact an Experienced New York Criminal Defense Attorney
Challenging a DWI charge can be complex and requires knowledge of not only the law — but also the science behind DWIs. The attorneys at D’Emilia Law offer reliable representation and experienced counsel for those arrested on drinking and driving offenses, and they work aggressively to obtain the best possible outcome in each case. To schedule a consultation, contact us at 1-888-DEMILIA.