All states have laws to combat drunk driving with various penalties, such as jail, loss of license and fines. However, police in Massachusetts and around the country can make mistakes when they conduct traffic stops, which may get a case dismissed.
Unlawful traffic stop
To test a driver for intoxicated driving, the officer needs reasonable suspicion or grounds to believe that a crime was committed. This may include a driver running stop signs, speeding, swerving or not using turn signals.
The officer also needs probable cause to make an arrest, which means collecting evidence of drunk driving. If they only saw the driver leave a bar or driving at night, it won’t be admissible as evidence.
Invalid field sobriety testing
Officers are required to observe drivers for 15 minutes to watch for signs of impairment before conducting chemical tests. They usually conduct field tests prior to the chemical testing to check for balance and ability to follow directions.
For example, the one-leg stand test asks the driver to balance on one leg for about 30 seconds. If the officer leaves out instructions or lacks the training to administer this test, it could cause the driver to fail.
Mishandling of chemical tests
Officers mostly use breathalyzer tests, which measure blood alcohol content levels using a breath sample, but these tests can give inaccurate results. Certain medical conditions, such as diabetes, may cause a false positive because it produces more acetones. The device must also undergo periodic calibration to ensure that the software is accurate, and it must be an accepted brand.
If the officer orders a blood or urine test, the samples must be stored properly to avoid contamination. Blood tests should only be administered by a qualified person, such as nurses or phlebotomists. The defense may challenge the test results if this requirement isn’t met.
Officers can also make mistakes at DUI checkpoints, which include misconduct. If a driver challenges police conduct and is still found guilty, they may be able to work out a plea deal for a lesser charge.