Some states in the U.S. now have two statutory offenses relating to DUI charges. The first is the traditional offense, variously called driving under the influence of alcohol (DUI), driving while intoxicated or impaired (DWI) or operating while intoxicated or impaired (OWI). The second and more recent offence is the so-called illegal (per se) offense of driving with a blood-alcohol concentration (BAC) of 0.08% (previously 0.10%) or higher (which remains the highest allowed level of blood-alcohol in the world). The first offense requires proof of "intoxication," although evidence of BAC is admissible in a court of law as "rebuttably presumptive evidence of that intoxication"; the second requires only proof of BAC at the time of being in physical control of a motor vehicle. An accused citizen may be convicted of both offenses, but may only be punished for one of the two. It is recognized as a criminal offense in all states to drive a vehicle while under the influence of drugs (DUID), or under the added influence of alcohol and drugs; the drugs themselves need not be illegal, but can be prescribed by a medical doctor or even "over-the-counter"! Yes, in some states, the effects of some herbal remedies (such as "Kava Kava" extract) fall into this category. This offense requires physical evidence of driving impairment as a result of the drugs or combination of drugs and alcohol -- although some states have passed laws making driving with the mere presence of certain strange/ street drugs a criminal offense, in and of itself -- its new, but on the books. Some states also include a lesser charge of driving with a BAC of 0.05%; other states limit this offense to drivers under the age of 21. All states also now have zero tolerance laws: the license of anyone under 21 driving with a BAC of .01% or higher (.02% in some states) will be suspended. The blood-alcohol limit for commercial drivers is 0.04%. Commercial drivers are also subject to stricter punishments for exceeding the blood-alcohol limit. Pilots of aircraft may not fly less than eight hours after consuming alcohol, while under the impairing influence of alcohol or any other drug, or while showing a blood alcohol concentration equal to or greater than 0.04 grams per decilitre of blood. The various versions of "driving under the influence" generally constitute a misdemeanor (punishable by up to one year in jail). However, the offense may be elevated to a felony (punishable by a longer term in state prison) if the incident caused serious injury (felony DUI), death (vehicular manslaughter or vehicular homicide), or extensive property damage (a state specified dollar amount) or if the defendant has a designated number of prior DUI convictions within a given time period (commonly, 3 prior convictions within 7 years). California, which is being followed by a growing number of states, now charges second-degree murder where the legal state of mind of malice exists"that is, where the defendant exhibited a reckless indifference to the lives of others.