When I am stopped for a DUI and the officer asks me to blow into the handheld machine at the scene should I do so? Am I required by law to do so?

You are not required by law to submit to the breathalyzer test that the officer offers you at the scene. We almost always suggest that our clients refuse to submit to the test at the scene. There is no legal penalty for refusing to do so and if in fact you are at .08 or above then they will not have that evidence to use against you. On the other hand if you had NOTHING to drink at all then it would probably be a good idea to submit to the test as it likely will read zero which is what you want.

However, you must legally submit to a blood or breathe test at the station. If you refuse to do so then the DMV will suspend your license for one year regardless of whether you ultimately are found guilty of a DUI.
If a person has many prior DUI’s he is facing a lengthy jail sentence if convicted. The person must take this into consideration in deciding whether to consent to the blood or breathe test at the station.