In most Rochester area DWI cases, the defendant’s blood alcohol content will be determined using a breath test machine.
However, in some cases – usually cases involving motor vehicle accidents or on occasions where a breath test machine is unavailable – the defendant may be asked or required to submit to an actual blood test to determine his or her blood alcohol content.
Because the blood of the defendant is being directly tested, a blood test is generally considered the most accurate method of determining blood alcohol content.
The primary reason it is used much less often than the breath test is that members of law enforcement can conduct a breath test at the police barracks and know the result almost instantly.
A blood test requires that blood be drawn by someone with the proper medical training to do so, which means either taking a defendant to a hospital or otherwise making arrangements to have a person with the necessary training available to draw blood.
Once the blood is drawn, it must be properly stored so that it does not become contaminated. It is then transported to a laboratory facility with the equipment to conduct the blood test.
At the laboratory, blood is usually tested using a technique called gas chromatography, which can test not only for alcohol, but also for a variety of other legal and illegal substances.
Because the test result is not obtained right at the police barracks, it may be several days before it is even known if the blood alcohol content supports any criminal charges.
As a result, a defendant who takes a blood test may find that he or she faces additional charges upon returning to court.
If you have taken a breath or blood test, you need the help of a DWI lawyer who understands the evidence against you. Call us at 585-484-7432.