Basics of Breath Testing for DWI in NJ


New Jersey DWI Breath Testing Attorney Explains Procedure, Evidence, & Legal Challenges

Most DWI charges in New Jersey are filed after a driver fails a breath test, otherwise known as a breathalyzer test. If the breath test results indicate that the driver was over the state’s legal limit, this will provide strong evidence of intoxication and help the prosecution to meet their burden of proof in court. But the breath test machine is not infallible, nor are the police officers who administer them. In fact, breath test results have been shown to be inaccurate many times. So, if you did test at or above 0.08% blood alcohol concentration from a DWI breath test, it does not mean that there is no hope in winning your drunk driving case. With the right defense strategy, it may still be possible for a skilled DWI lawyer to challenge the validity of the breath test result and successfully challenge your DWI charge. The drunk driving defense lawyers at our New Jersey firm have enhanced training and credentials for the operation, calibration, and assessment of the Alcotest breath testing device used to measure a driver’s BAC when suspected of driving while intoxicated. Call our office in Edison, NJ if you have been charged with a DWI anywhere in Middlesex County or elsewhere in the state. You can receive a free DWI attorney consultation by contacting (732) 659-9600 or schedule an appointment to meet with us in person.

How Breath Testing Works in New Jersey

Breath tests are an important part of the DWI arrest process by law enforcement in New Jersey. When you are first pulled over by police, they may administer field sobriety tests or a portable breath test (PBT) at the scene. You are not legally obligated to take either of these types of tests, but police can still arrest you even if you refuse. The PBT is a quick, and often inaccurate, test that will provide an initial measurement of your blood alcohol concentration (BAC). If the portable breath test shows that you are above the legal limit for BAC, this will give police the probable cause they need to place you under arrest. But the portable breath test results will not be admissible in court as proof that you were driving while intoxicated. In order for prosecutors to prove that you were drunk, they will have to introduce evidence from a Drager Alcotest machine, which is the device used by New Jersey law enforcement for all DWI cases.

The Drager Alcotest device, also known as a Breathalyzer, is larger than a portable breath test, and it is administered at the police station. The driver blows a sample into the machine, which then uses infrared radiation to pick up ethanol molecules from the sample to determine the amount of alcohol in the person’s bloodstream. If the driver registers a BAC of at least .08%, they will have reached or exceeded the legal limit and can be charged with a DWI.

The process for calibration, maintenance, and administration of the Alcotest machine is mandated by law in New Jersey. The machine needs to be calibrated for accuracy and regularly checked by trained personnel to ensure that it won’t malfunction or show false positives during use. These inspections must be performed monthly. Additionally, the police officer who administers the breath test to the DWI suspect must be specially trained and obtain a license for the machine.

New Jersey Breath Test Results as Evidence in DWI Cases

Your DWI case will be heard by a judge in the Municipal Court located in the city or town where you were pulled over and arrested by police. At trial, the prosecution will need to prove beyond a reasonable doubt that you were impaired by alcohol or drugs while operating your vehicle in order to secure a conviction for DWI charges. The most common way for prosecutors to prove that a motorist was intoxicated while driving is to introduce evidence in the form of a breath test reading that shows the motorist to have been operating their vehicle with a blood alcohol concentration (BAC) of .08% or higher.

Keep in mind, however, that a breath test is not the only way for authorities to prove intoxication in a DWI case. That’s because a police officer’s observations at the scene of the traffic stop or DWI accident can also be used as proof that the driver had consumed alcohol and was above the legal limit. For example, certain visual and other sensory cues – bloodshot eyes, slurred speech, the odor of alcohol on the driver’s breath, an open container of alcohol in the vehicle – can provide further proof to establish that the motorist is intoxicated. Note that you can still be charged with a DWI even if you didn’t feel drunk at the time of the arrest.

What Happens if You Refuse an Officer’s Request that You Take a Breath Test in NJ

Since breath test results can be used against you in a DWI case, it might seem like a good idea to refuse to submit to a breathalyzer when asked to do so by police. But this would be a very bad idea because it is actually against the law to refuse a breath test: all motorists in New Jersey automatically consent to breath testing the moment they get their driver’s license. Moreover, N.J.S.A. 30:4-50.4a allows judges to impose severe penalties against anyone who is convicted of DWI Breath Test Refusal charges. These penalties vary, depending on whether the offender has prior convictions for either Refusal or DWI on their driving record. In addition to facing charges for Breath Test Refusal, you can still be charged with a DWI because the police officer’s observations and other circumstances of the case may suffice as convincing evidence that you were drunk while operating your car or truck. To make matters worse, the sentence for a DWI conviction and the sentence for a Refusal conviction may be imposed consecutively, which means that the penalties could be stacked on top of each other.

Defense Options to Invalidate Breath Test Results for New Jersey DWI Charges

Anyone who faces DWI charges involving a breath test and related blood alcohol reading should speak with an experienced DWI attorney who understands how the breathalyzer works and how you may be able to challenge the evidence in court. The truth is that there are a number of potential issues with breath test machines and results that can offer viable DWI defense strategies for getting the breath test reading suppressed. This would mean that the prosecution could not use the breath test results against you as proof of intoxication at trial.

Some of the strongest defenses against breath test results include the following:

  • There was no probable cause for the traffic stop. If the police officer who pulled you over on the road did not have reason to believe that you were committing a traffic violation, then any evidence of intoxication that they obtained after the initial vehicle stop could be ruled inadmissible under the “fruit of the poisonous tree” doctrine.
  • There was no reasonable suspicion that the driver was drunk. Even if the police officer had probable cause to pull over your vehicle, that still does not establish reasonable suspicion that you were intoxicated. Before the police can ask you to take a breath test, they must have some rational basis for believing that you are intoxicated.
  • The police failed to provide clear instructions. The police must follow certain procedures when requesting your consent to submit to a breath test. For instance, the officer must advise you of your rights and read you the standard refusal form before you take the test, not afterwards. Additionally, the officer must make sure that you speak English and can understand their instructions. Any ambiguity in the officer’s instructions could give the judge a reason to block the use of the breath test results in court.
  • The driver had a medical condition. Sometimes, a breath test can give a false positive because the person taking the test has a medical condition like acid reflux, asthma, or some other respiratory issue. The same thing can also happen if the breath test sample is collected from someone with dentures in their mouth. If there is any uncertainty that the results are valid, the judge may order that they cannot be used at trial.
  • There was a mistake during administration of the test. Police must follow strict procedures when administering breath tests to DWI suspects. For example, police must observe the suspect for at least 20 minutes before starting the test, and they must collect two breath samples during the test. Additionally, the technician responsible for administering the breath test must be licensed to do so. If their license has expired, then any results from tests they administered may be invalid.
  • Too much time passed before the driver took the breath test. The entire process for administering the breath test can be a lengthy one. First, police must pull you over on the road, investigate to determine whether you should be arrested, and then physically transport you to the police station. Once you are at the police station, you must be observed for 20 minutes before police can administer the Drager Alcotest. If more than two (2) hours elapsed from the time when you were actually driving until the time when you took the breath test, it could affect the breath test results.

Who can Help Use Breath Test Issues to Avoid a Drunk Driving Conviction in NJ

The highly skilled DWI defense attorneys at our Middlesex County law office have challenged and beaten a multitude of drunk driving cases based on invalid and inadmissible breath testing administration and results throughout New Jersey. If you have been charged with driving while intoxicated by alcohol in towns like Piscataway, New Brunswick, Old Bridge, Monroe Township, Perth Amboy, East Brunswick, or Edison, explore your defense options with our lawyers’ help by calling (732) 659-9600 or sending us a message for a free consultation.

William Proetta

With more than a decade of experience defending clients against criminal charges, founding partner William A. Proetta has successfully handled and tried thousands of cases, from DWI to murder. As a New Jersey native, he has focused his career on helping people in the area where he grew up, serving Middlesex, Ocean, Hudson, and Union counties.