You have been arrested, you are at the jail, you are alone, you are tired and you are scared. A police officer asks for a sample of your breath or blood, and you correctly refuse. The next issue that comes up is whether the officer can force you to give a sample of your blood whether you consent or not.
The answer is that yes, your blood can forcibly be drawn, but generally only after a search warrant has been signed.
A sworn affidavit from police establishing probable cause is the first step in obtaining a search warrant. Additionally, a judge reviewing the affidavit for probable cause can only make reasonable inferences based on the information in the affidavit and cannot go beyond that information. The affidavit needs to show that the totality of the circumstances reflected in the affidavit provided the magistrate a substantial basis for deciding that probable cause existed.
The law states that a search warrant affidavit must establish that 1) a specific offense was committed (DWI for these purposes), 2) the item to be seized constitutes evidence of the offense or evidence that a particular person committed the offense (for these purposes, blood), and 3) the item is located at or on the person, place, or thing to be searched.
How do you determine whether or not a judge was actually provided enough specific information to determine that probable cause exists in your case and that therefore the police legally forced you to give a blood sample? There is no magic formula for determining probable cause. It is really a common sense approach that the courts take on these cases. Did the information provided in the affidavit and the reasonable inferences a judge made or could have made provide him or her with probable cause?
However, if too many inferences must be made then perhaps that affidavit didn’t provide enough specific information and instead forced the issuing judge to decide on the periphery of what constitutes probable cause. If that is the case then there is a real possibility that the warrant that was issued was done so in violation of the Constitution. If a warrant is issued in violation of the Constitution then there are remedies that you are entitled to and some of those remedies will prevent the State from presenting any evidence obtained as a result of the warrant.