Can you challenge evidence from a DUI traffic stop?

by | Jun 11, 2019 | Firm News

In the past, law enforcement has made significant errors during DUI traffic stops. The protocols, procedures and devices are far from 100% accurate. In addition, law enforcement officers, like other human beings, make mistakes. Therefore, you can bring many aspects of a DUI traffic stop into question.

Typical law enforcement errors made during DUI traffic stops

New Jersey requires law enforcement to follow a defined set of procedures and protocols for a DUI stop.

Common problems and failures include:

  • Improper Stop: The officer must have a reasonable suspicion to make the traffic stop. For many different reasons, the defense can argue that the officer did not have a reasonable suspicion to make the traffic stop in the first place.
  • Unreliable field sobriety tests (FSTs): While law enforcement has used standardized FSTs for about 40 years, that does not make them highly accurate nor reliable. According to Fieldsobrietytests.org, the horizontal gaze nystagmus is about 77% accurate, the walk-and-turn is 68% accurate and one-leg stand rates as 65% accurate. In many instances, these FSTs only indicate a sign of alcohol impairment and not the fitness to drive a car. Defendants frequently find grounds to challenge field sobriety tests in court.
  • Breath test machine issues: Breath test machines are complex electronic instruments, and as such, they need to be properly calibrated and maintained. If the law enforcement agencies do not perform this on a routine basis, the accuracy of the machines declines. An officer must be adequately trained to use the breath test machine. If the officer incorrectly administered the test, the results may not be admissible in court. If these or other factors apply to your case, you may be able to challenge the breath machine results.

While this is not a complete list, these issues have led to inaccurate and unreliable DUI charges. You need to realize there are many different potential problems with DUI traffic stops. For these reasons and others, many aspects of a DUI traffic stop may be challenged in court.