The legal limit for blood toxicity is .08 percent. If you are stopped by police with a blood alcohol concentration over the legal limit, then you could be arrested for driving under the influence of alcohol. If you are under age and have a blood alcohol concentration of .01 to .02 percent, you could be considered to be under the influence of alcohol even though it won't affect you in the same way as having a blood alcohol concentration of .08 percent. This is because the authorities do not want people underage driving while intoxicated and penalize them more heavily if they are found to have any alcohol in their test results.
Police identify those who are driving under the influence in a number of ways including observing erratic driving, like speeding or weaving in and out of lanes, providing field sobriety tests and testing chemical blood alcohol levels by taking breath, blood or urine samples.
If you are stopped by police and asked to provide a breath test, then you should do so in most cases. If you refuse, it's possible that you could have your license revoked even though you may not be found guilty at a later date. You have the right to speak with your attorney after the test, so you can begin to develop a defense.
There are a variety of defenses for your case ranging from proving you weren't drunk to showing that police didn't have a reason to pull you over. Our website has more information on the defenses that might work best for your case, so you can work to reduce penalties or have your case dismissed.