Massachusetts residents may be curious about what types of tests to expect if they are pulled over by a police officer who thinks they may have been drinking. There are three types of field sobriety tests endorsed by the National Highway Traffic Safety Administration.

The first test that an officer might use to determine whether someone has been drunk driving is the horizontal gaze nystagmus (HGN). A person who is under the influence of alcohol or drugs may have trouble focusing on a moving object, so the police officer may try to get the driver to stare at a moving finger while the officer examines his or her eyes for jerking movements.

The other two tests are both classified as divided attention testing as they ask the driver to complete tasks that can be easily accomplished by most sober people. The test looks at the person’s ability to listen and follow instructions in addition to whether they are able to complete the given tasks. The first test requires that the driver walk nine steps in a straight line, heel-to-toe. The second test requires the driver to stand, one foot hovering in the air, counting aloud, until the officer directs him or her to stop. The test lasts 30 seconds.

Operating under the influence is a charge that can impact a person’s future. A criminal defense attorney may be able to help challenge the efficiency of the field sobriety tests or suggest alternate reasons that a person did not successfully complete those tests. It may also be possible for an attorney to help negotiate a plea bargain for a lesser offense or seek to minimize punishment in exchange for a guilty plea.

Source: National Highway Traffic Safety Administration, “Highway Safety Desk Book”, November 22, 2014