There are several reasons Rochester area police agencies prefer to use a breath test to prove blood alcohol content as opposed to blood test, even though the blood test is considered more accurate.
One of these reasons is that the blood tested often must pass through several hands between the time it is drawn and the actual test, which can create concerns about possible mistakes in testing or tampering.
Once it is drawn, the defendant’s blood is considered evidence that is in the custody of law enforcement, and law enforcement must establish a clear chain of custody from the time of the blood draw until the blood test is performed.
As a result, at the time of the blood draw the vials containing the blood should be labeled and sealed. This seal should not be broken until the blood is ready to be tested.
Also, the entire chain of custody should be clearly documented.
It is not unusual for one member of law enforcement to place the kit containing the blood vials in cold storage until another member of law enforcement can deliver it to the lab for testing.
At the lab, an employee will again place the blood in storage until it can be tested.
An experienced DWI lawyer may look into the documentation surrounding the blood draw to ensure that the vials were properly labeled, the chain of custody was fully documented, and there was little possibility that the defendant’s blood was tampered with or that a mistake in labeling may have resulted in the wrong blood being tested.
A breath or blood test result is often the most damaging piece of evidence against a defendant.
If you are facing a criminal charge based on a breath or blood test result, you need an attorney who will examine all of the evidence against you.
Call us for legal help at 585-484-7432.