Evidence in New Jersey DWI Cases, Part 2: Chemical Testing

The state has the burden of proving guilt beyond a reasonable doubt in New Jersey driving while intoxicated (DWI) cases. A defense attorney’s job, in part, is to identify defects or deficiencies in the state’s case. DWI cases often require a considerable amount of documentation. Under the DWI statute, a person is guilty of DWI if they operate a vehicle while under the influence of alcohol or drugs, or while their blood alcohol concentration (BAC) is at least 0.08 percent. Police can determine BAC by testing samples of breath, blood, or urine. Breath testing is most common, followed by blood. Each type of testing requires proof that police followed specific procedures. The evidence must meet standards set by the New Jersey Rules of Evidence (NJRE), state law, and court decisions.

Authentication of Documents

In a courtroom, BAC evidence generally takes the form of written reports. In the case of breath testing, this is usually a series of reports generated by the Alcotest device. BAC results obtained from blood samples involve reports from the laboratory that performed the test. NJRE 901 requires authentication of all documents offered as evidence, meaning evidence that the document is, in fact, what the party offering it claims it is. This can be accomplished by having the person who created the document authenticate it in sworn testimony. Some documents are “self-authenticating,” as described by NJRE 902.

Breath Samples – State v. Chun

State v. Chun is a 2008 decision by the New Jersey Supreme Court that established guidelines and standards for Alcotest devices. These include guidelines for the maintenance and calibration of the devices, as well as procedures for obtaining breath samples from DWI suspects.

The case identified specific evidence that the state must produce in order to establish the reliability of the results and compliance with Chun. It must produce the operator who administered the test as a witness. At a minimum, the state must also produce three documents:  the most recent calibration report for the device prior to the defendant’s test, the most recent “standard solution report,” and the “certificate of analysis” of the solution used by the device in the testing process.

Blood Samples – Proper Medical Procedures

The Alcotest device allows the collection and testing of a breath sample all at once. Blood samples are more complicated. A trained medical professional must collect the sample by following procedures specified by state law. They must then issue a certificate, signed before a notary public, indicating that the blood sample was obtained “in a medically acceptable manner.”

Blood Samples – Chain of Custody

Once police have obtained a blood sample, they must deliver it to a laboratory for testing. The state must be able to demonstrate a chain of custody for the sample to ensure that no errors occurred, such as samples getting mixed up.

Blood Samples – Privileges

State law includes provisions for the collection of a blood sample by a medical professional upon the request of a law enforcement officer or subject to a court order. When blood is collected as part of a person’s medical treatment, the patient-physician privilege may preclude the introduction of any information obtained from that sample as evidence. The New Jersey Supreme Court addressed this in a 1984 decision, State v. Dyal.

If you have been charged with DWI in a New Jersey municipal court, DWI lawyer Evan Levow can advocate for your rights and prepare your defense. Contact us today online or at (877) 593-1717 to schedule a free and confidential consultation with a member of our experienced and skilled team.

More Blog Posts:

Evidence in New Jersey DWI Cases, Part 1: Testimony, New Jersey DWI Attorney Blog, December 19, 2017

New Jersey Appellate Court Reverses DWI Conviction Based on Warrantless Blood Draw, New Jersey DWI Attorney Blog, November 30, 2017

New Jersey DWI Law and the “Quasi-Entrapment” Defense, New Jersey DWI Attorney Blog, October 27, 2017

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