The conviction rate in DWI chemical test cases is about twice as high as the conviction rate in non-test cases. Even still, only about 20 percent of DWI defendants refuse to provide a breath or blood sample.
Frequently, police officers bully suspects into submission with tales of mandatory license suspension and the fact that test refusal is admissible in court. A good Fort Worth criminal defense attorney can overcome these hurdles, but of course, police officers don't tell people that.
The reason for the conviction rate discrepancy is that, in non-test cases, prosecutors normally must rely exclusively on the three approved Field Sobriety Tests. Frankly, given the flaws in these tests, it's surprising the non-test conviction rate is as high as it is. That's a credit to the ability and tenacity of Tarrant County prosecutors. You need an equally strong advocate on your side.
Horizontal Gaze Nystagmus
The DWI eye test is usually the first FST that police officers administer. It is also the weakest one.
Most people have probably taken one of these tests in the doctor's office. Subjects follow moving eyes, such as ink pens, with their eyes without moving their heads. If the subject's pupils move involuntarily at certain angles, the subject probably has nystagmus.
Alcohol does cause this condition, which is also known as lazy eye. But it's not the only cause. In fact, it's not even the leading cause. Many people have a lazy eyes but they do not know it because the symptoms are so mild.
Furthermore, roadside HGN tests are much less reliable that laboratory HGN tests. For example, in the field, the flashing lights atop the squadcar cause flicker vertigo, which is a form of visual disorientation.
The OLS is a divided attention test which measures both mental alertness and physical/balance ability. Supposedly, people who are intoxicated are biologically incapable of engaging both these parts of their brains at the same time.
For this test, the defendant must elevate one leg to a certain angle, usually forty-five degrees, and stay that way for a while, usually about fifteen seconds. During the test, the officer looks for intoxication clues, like:
Lifting the wrong leg,
Holding the leg at the wrong angle,
Using arms for balance,
Putting the leg down too early.
This test is almost impossible to successfully complete if the defendant has any illness, injury, or mobility impairment. Furthermore, officers routinely testify that defendants "failed" the test because of minor technicalities. But the jurors decide who passed and who failed, and their conclusion is the only one that counts.
Walk and Turn
The heel-to-toe walk is another divided attention test. The defendant must walk a straight line heel to toe, then turn around and walk back.
Environmental factors affect this test. It's almost impossible to walk an imaginary line heel to toe. It's even harder in the dark. Furthermore, officers are supposed to ask defendants if they have an illness or injury and give them a chance to do this test barefoot. But they don't always do these things, and these accommodations are not always practical.
It is hard to use circumstantial evidence to establish guilt beyond a reasonable doubt. For a free consultation with an experienced criminal defense attorney in Fort Worth, contact Herreth Law. Convenient payment plans are available.