DUI (driving under the influence) charges can be crippling. Depending on the severity of the DUI incident, the BAC of the driver and the driver's prior DUI history, the charges can bring heavy fines, long jail terms, felony convictions and the loss of a driver's license. Although there is a national standard for determining what constitutes a DUI (a blood alcohol content of .08% of higher), most states have their own additional laws. Some states have penalties for simply having a BA of .05%. All states have zero tolerance for anyone fewer than twenty-one who are caught drinking. In addition, more and more states are applying mandatory sentences to DUI offenses. Police can charge a driver with a DUI offense do to probable cause brought on by erratic driving, DUI checkpoints, and traffic and accident investigations in which field sobriety tests or breath analyzers show the presences of alcohol in the driver. If anyone if facing a DUI charge, a DUI lawyer should be consulted immediately, as a DUI lawyer is well versed in protecting a client's rights and interests.