What Are Your Rights When Police Request a Blood Sample?

Your Rights When Police Draw Blood

UPDATE: Nov. 27, 2019

A Court of Appeals ruling triggers revisions of Massachusetts OUI consent forms.

The court’s determination that the term “chemical test” as used in Massachusetts’ statutory rights and consent form is not clear enough. This means changes will be coming to the standard form that police typically use to read OUI suspects their rights under the implied consent statute.

This is what Attorney Oberhauser said to Massachusetts Lawyers Weekly.

Chelmsford attorney Gregory D. Oberhauser said the language of the state’s statutory rights and consent form has long been a bone of contention for the OUI bar.

“A lot of the times in the booking videos you’ll see the [officer inform the defendant,] ‘I get to choose which test you’ll get, whether it’s breath or blood,’” Oberhauser said. “But when you read the form, it doesn’t advise you [that you’re consenting] to a blood draw.”

If you have any questions about how this could be applied to your current OUI case give us a call for a consultation. 978-452-1116


The U.S. Supreme Court has recently made some important rulings related to OUI investigations and blood draws for blood-alcohol testing. The most important among these is the ruling that law enforcement officers are in violation of your 4th Amendment rights if they draw blood from you without a probable cause warrant, or your consent.

What this means for Massachusetts drivers is that before police can order blood drawn from you for OUI BAC testing purposes, they need to either:

1.   Get a search warrant from a judge or magistrate based on probable cause, or
2.   Obtain your explicit consent *(See hospital exception below).
3. Or, if law enforcement believed an emergency existed, then prosecutors must show how / why the emergency prevented police from acquiring a warrant before the court can allow warrantless, unconsented BAC results into evidence.

This has become known as the Birchfield Law, the 2016 Supreme Court ruling on DUI blood tests that determined drawing blood is an intrusive act against personal privacy, and thus prohibited under your Fourth Amendment rights —unless a warrant or your consent is obtained.

It should be noted that in the same ruling, the Court held that warrantless breath tests after a lawful DUI arrest are still permissible.

If a warrant is not properly obtained before police take a blood sample for BAC testing, your OUI lawyer can file a motion to suppress the results from evidence.

Your case can be better positioned for dismissal or an acquittal if the blood-alcohol content (BAC) is kept out of evidence due to lack of a search warrant or your consent.

Supreme Court Ruling & MA Implied Consent Laws

The Supreme Court of the United States also decided a DUI case that dealt with implied consent laws and refusal statutes.

In this decision, the SCOTUS ruled that criminalizing a driver’s refusal to submit to BAC testing undercuts the notion of voluntary consent. Free and voluntary consent is an acceptable exception to government searches and seizures.

As a result, states cannot make separate crimes for DUI test refusals. Nor can they impose criminal punishments and penalties for a refusal. Massachusetts no longer does.

But the Court held that civil or administrative penalties are fine.

Now, Massachusetts classifies penalties for chemical test refusals as administrative sanctions; meaning the Registry of Motor Vehicles will punish you by suspending your license.

Related Information

  1. Know Your Rights During DUI Stops
  2. How to Beat a Hospital Blood-Alcohol Test
  3. What Not To Do at a DUI Checkpoint

What If I’m brought to a hospital after a car accident in Massachusetts?

If you are the driver of a vehicle involved in an accident in this state, you should know that under MA law, your consent to a blood draw is considered implied if you are brought to a hospital or clinic for medical treatment.

** Important: This law can be successfully challenged in court given recent Supreme Court decisions concerning true consent. If you were not informed that your blood would later be sampled by the police, you may have a legal argument to suppress any blood-alcohol results obtained from the hospital’s blood draw. **

If you still choose not to consent at the hospital, understand that the refusal law yields driver license suspensions for refusing DUI blood testing.

While Massachusetts consent laws for OUI blood tests are on shaky legal ground, you should protect your rights by knowing that:

  • Police cannot accept a DUI suspect’s consent to a blood draw if the driver has diabetes; or
  • If the driver has hemophilia, or
  • If the DUI suspect has any condition for which anticoagulants would be necessary.
  • Law enforcement should present hospital staff with a search warrant in order to take custody of a suspect’s remaining blood samples, and
  • Police should never attempt to forcibly draw blood from you or hold you down while a medical worker draws your blood!
  • If police arrest you for OUI, inform you of your rights under implied consent, and you still refuse blood testing, your driver’s license will be immediately suspended for a minimum of 180 days.

If a vehicle accident renders the suspect unconscious, blood should not be taken for drug or BAC testing purposes.

However, this isn’t yet the standard in Massachusetts. You may have a winnable case. You can contact my law office for an obligation-free case evaluation: 978-452-1116.

Related Q&A: What are my constitutional rights when I get pulled over?

You have the constitutional right not to incriminate yourself during any police stops. You can respond clearly (and repeatedly, if needed) that “I do not answer questions.”

Fourth Amendment rights protect you from unreasonable searches and seizures without issuance of a warrant. This includes searches of your body and your blood.

You have the right to preserve evidence that may be related to your innocence.

The Sixth Amendment gives you the right to confront any accusers and witnesses against you in a criminal proceeding.

This means all medical workers and lab technicians who processed your blood must be present at trial!

What Can You Do If You Are Unsure of Your Rights?

A traffic stop by law enforcement must be based on a reasonable suspicion that a law has been broken. A stop is considered unlawful if no reason existed (violated your search and seizure protections).

You still have rights even if you are injured in a car accident and taken to a hospital. Furthermore, your constitutional rights do not cease to exist when and if you were rendered unconscious.

Any number of your state and constitutional rights may not have been properly observed by law enforcement. That is why you should talk to a criminal defense attorney in Massachusetts as soon as possible.

Defense strategies involving constitutional violations often lead to case dismissals or acquittals.

Moreover, as a forensic lawyer-scientist, I know that many OUI blood tests performed in this state are prone to serious errors. These flaws can be demonstrated to the judge with the right scientific training and legal skills.

If you’d like to see how I’ve helped successfully defend against all types of Massachusetts motor vehicle offenses, visit my case results page.


For immediate emergency assistance after hours, call my office at 978-452-1116. The answering service will reach me and I will promptly call you back.

Attorney Gregory Oberhauser

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Gregory Oberhauser is the ONLY attorney in Massachusetts to be distinguished as an ACS-CHAL Forensic Lawyer-Scientist by the American Chemical Society!

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