You can refuse the preliminary alcohol screening device that they give you at the scene, but you cannot refuse to take a blood or breath test. If you do, it's disasterous for your license and can actually add time to a DUI sentence (assuming you're found guilty in the end). Each has it's pros and cons for both sides, but neither is necessarily "better" than the other.
Mr. Feasel is a former Deputy DA in the SF Bay Area with over 10 years of criminal law experience. Nothing stated on this site shall in anyway be construed as legal advice, or as creating any attorney/client relationship. If you would like to hire Mr. Feasel to further investigate your situation, feel free to contact him thru this site.
I advise refusing the PAS test on the scene, because that is optional and will only be used against you. I would then advise choosing a breath test, because breath tests are less reliable and easier to attack. If you can cause a whole lot of time to elapse in the meanwhile, such as by asking for a blood test and then changing your mind and switching to a breath test when they take you to the hospital for a blood draw, you will have created more opportunity for your defense. But, the best option of all to beat a DUI, is to not drink and drive.
You must submit to an evidentiary test for a DUI. A PAS test can be refused. Both tests have their pros and cons. A breath test is easier to question.
Your question is one which attorneys debate all the time. Some think you should take the breath test because the machine is open to attack. On the other hand, the machine is open to attack is because it is error ridden. You don't want to blow into a machine and have it read .09 - when your BAC was actually lower. In that scenario it would be better to take the blood test.
You can also attack the blood test such as the methods of storage, blood draw, etc. Sometimes the DA forgets about calling the correct witnesses to trial to lay the foundation for the blood. Sometimes the blood gets lost. I know of a case where the blood was retested and it had another persons name on the vile and not the defendants.
Now back to your question. I do not know which is better. Both have their strengths and weaknesses.
The above information does not establish an attorney client relationship nor is it meant to provide legal advice.
The question you need to ask yourself, what is in my system? If you only have alcohol in your system, a blood test is more accurate and the blood can be retested for your Blood Alcohol Level, your Blood Type, and the amount of preservative in the blood container. (Very important...)
If there's any other substance in your system, such as marijuana or prescription medication, the prosecutor can retest the blood sample for everything in your blood.
If more than alcohol is found in your system, it makes the case much more difficult to fight in the criminal court. As for the DMV, you would need to call my office.
Sign up to receive a 3-part series of useful information and legal advice about DUIs.