How is a DUI determined (various ways)?
There are a few ways which allow law enforcement to determine whether or not a person is DUI. The most common would be the blood-alcohol level count. If a breathalyzer determines a BAC count of .08% in people 21 and over, that could be grounds for a DUI. Some states even have this limit at .05%, and drivers of commericial vehicles are capped at .04%. The BAC for DUI in peoples under 21 is usually around .01% or .02%, as there is also the issue of underage drinking to contend with.
Some places treat DUI’s as more civil than criminal, so the necessity for substantial evidence is lesser in some parts of the US. Different ways of testing the BAC include breath tests, blood tests, or chemical tests.
DUIs may also be determined by field-sobriety tests. Rather than relying on a BAC to create a conviction, a police officer can use a standarized group of tests of motor skills to determine whether or not a person may be under the influence of some substance. These are generally useful, and used, in instances where clearly impaired driving it noticed.
