You can be convicted under 23152 (a) vc for driving while impaired. A BAC of .03 only means the level of alcohol in in his blood at the time he was tested. Drugs, prescription medicines, nyquil, etc. can also impair one's driving and lead to a conviction. Get an attorney to deal with this ASAP.
In California you may be charged for DUI under two sections, one is if you are at a .08 or above, and the second section allows for a DUI where the person is "under the influence of alcohol and/or drugs". To find someone "under the influence" the prosecution would have to show they were "impaired" by the substance. The prosecution would look to the driving, field sobriety tests, other observations and statements to try and prove the case. It is much harder to prove a DUI under these circumstances.
Yes, you can be convicted of a DUI with a .03. Realistically, however, unless there was drug use or VERY bad driving, or perhaps a statement by your friend to police like "wow I feel really drunk and am driving poorly because of it" it is most likely the prosecutor will decline to file charges.
He may be charged under section VC 23152(a) (a misdemeanor), as there is no BAC limit associated with this charged. The other attorneys described this charge and the difficulty prosecutors may have in proving this case. However, is your friend under the age of 21? This affects whether he can be charged under Vehicle Code Section 23136 (unlawful to be under 21 and drive with a BAC above .01%). This is a civil offense enforced by the DMV. Vehicle Code Section 2340 makes it unlawful for a person below the age of 21 to drive with a BAC above .05% (an infraction). It is important to know precisely what your friend is being charged with, and the circumstances of the arrest. For instance, based on the timing of the test, prosecutors may argue that your friends BAC was above .03% at the time of driving (and therefore more likely to be impaired). Talk to an attorney to make sure the charge is appropriate, and prosecutors are held to prove that charge.
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