People v. Mertz case , 68 N.Y.2d 136 (1986)

People v. Mertz

At approximately 1:30 A.M. on the evening of April 19, 1983, Officer Sprague of the Nassau County Police Department was called to the scene of an accident near Bayville Avenue. When he arrived, he discovered motorist Edward Mertz dazed and injured behind the wheel of his car.  Officer Sprague called an ambulance, but noted Mertz appeared to be intoxicated and planned to follow up once the injured man was under hospital care.

Around 2:00 A.M., about half an hour later, Sprague arrived at the hospital where Mertz was being treated, and placed him under arrest on suspicion of DWI (Driving While Intoxicated).  However, because of Mertz’s medical condition, Sprague had to call the Highway Patrol Bureau for assistance with a breathalyzer test.

Officer Needleman arrived at the hospital around 2:40 A.M., obtained Mertz’s consent to proceed with a breathalyzer, and began the first test around 3:25 A.M., nearly two hours after the actual accident.  His first reading yielded a BAC of 0.15, with a second reading taken 10 minutes later displaying a slightly increased BAC of 0.16. Needleman justified the second reading by saying the first was insufficient, and Mertz was charged with and found guilty of DWI under New York Vehicle and Traffic Law § 1192 (2).

However, that was not the end of the case.  Mertz appealed the ruling, and defense attorney Victor Knapp successfully argued that his client had been improperly denied the opportunity to demonstrate a BAC of less than 0.10 at the time of the accident, that the breathalyzer logs were not properly admitted, and that an additional charge under Vehicle and Traffic Law § 1194 (9) was improper.  The jury reversed its original decision, and today the effects of People v. Mertz  continue to reverberate in thousands of DWI cases.

Are Breathalyzers Reliable?

Breathalyzers are notoriously fraught with shortcomings, and numerous legal and scientific professionals have questioned their accuracy and reliability in recent years.  In People v. Mertz, the primary issue involved was the timing of the test: Mertz was given a breathalyzer full hours after his crash.  However, even when tests are taken immediately following an accident, breathalyzers continue to frequently produce “evidence” which ranges from questionable at best to wholly inaccurate at worst.

For example, in the summer of 2010, Washington D.C. city officials revealed that since 2008, nearly 400 people had been convicted of DWI on the basis of readings from breathalyzer machines which were improperly calibrated by local police.  The District Attorney reported that all 10 of the devices used by city law enforcement were incorrectly adjusted, and routinely displayed readings which were a full 20% higher than what they should have been.

More recently, in August of 2013, retired Franklin County Municipal Judge Teresa L. Liston was appointed by the Ohio Supreme Court to review eight cases in which DUI defendants were challenging the BAC results of the Intoxilyzer 8000, a model commonly used by law enforcement throughout the country.  On August 13, after a five-day hearing, Judge Liston ruled that the Intoxilyzer 8000 readings in question were “not scientifically reliable and the court, as a gatekeeper against unscientific evidence, must prohibit them from being introduced as evidence in this case.”  While the Intoxilyzer 8000 remains in use today, more and more defendants are beginning to challenge its “presumption of reliability.”

Problems which can be detrimental to accurate breathalyzer readings include high heat or humidity, incorrect calibration, the rate at which the person being tested is breathing, and even certain medical conditions.  For example, having diabetes can affect the levels of acetone in the body, which can subsequently produce inaccurate readings.