You do not have to do field sobriety tests if you are stopped for a DUI and you shouldn't. These tests are very poor indicators of whether or not someone has had too much to drink to drive safely. The police sometimes exaggerate your test performance to make you seem more intoxicated. Furthermore, even if you do well, the experts for the prosecutors will say that just means you have built up a tolerance to alcohol. If stopped, polity explain to the officer that you have been told not to do the tests. This includes the hand held breath test. (You do have to do a blood or breath test after you are arrested.)
The police will try and convince you to do the tests anyway. You do not have to do them and the police cannot make you. They may tell you that if you do not do the field sobriety tests, they will have to arrest you. IF THEY HAVE DECIDED TO ARREST YOU IF YOU DON'T DO THE TESTS, THEY ARE GOING TO ARREST YOU NO MATTER HOW WELL YOU DO.
Also, do not make the mistake of saying you could not do the tests sober. That is a tacit admission that you are not sober. You should decline to do the field sobriety tests and decline to answer any questions. Don't give the police the ammunition they are going to use to get you convicted. Again, remember, you do have to do a blood or breath test after you are arrested.
If you have been arrested for a DUI or know someone arrested for a DUI and would like a free consultation, please contact our office (619)258-888.