In most cases, police officers try to give you a breath test as soon as they suspect that you are under the influence. They may have you do field sobriety tests first, or they may just talk to you and then administer the test.
However, this isn’t always possible. An officer may not have a test with them. They could determine that the test they do have is not working properly. They may want to take you to the station to do a different type of test, like a blood test. They may have other things to worry about — maybe you got into an accident — and put off giving out the test.
No matter why it happens, a significant amount of time can pass between when they pull you over and when they find out what your blood alcohol concentration (BAC) actually looks like. They may use this when determining if you deserve DWI charges.
For instance, say that you have a BAC of .07%. The legal limit is .08%. However, you had been in the car for an hour before getting stopped, and then another hour and a half passed before the test. Even though you did not exceed .08% during the test, they can sometimes argue that you were behind the wheel with a BAC that was over the limit. They know that BAC drops with time.
That said, these types of inferences can make things a bit more complicated than they would be otherwise. Those facing DWI charges in New Jersey need to understand all of their legal defense options.