After a crash, the State can obtain blood evidence in three ways: an officer can direct a draw under the implied consent law, a judge can issue a search warrant, or a prosecutor can subpoena a sample or records the hospital already has. Each route has its own legal requirements, and blood obtained outside them can be suppressed. This page explains the routes and two recent Montana Supreme Court decisions that apply them. It is part of our Montana DUI Guide.
Two Kinds of Blood Draw at a Hospital
The first is a medical draw. Emergency staff take blood to treat you, and the testing they order may include alcohol. It is not done at the request of law enforcement.
The second is a forensic draw. An officer asks staff to take a sample for the investigation, using a state collection kit, and it goes to the crime lab. The forensic collection rules apply to this draw. They do not apply to blood "drawn or analyzed by medical staff for medical diagnostic or treatment purposes, and not at the request of a peace officer" (ARM 23.4.220(1)).
One patient can have both. Start by finding out which sample produced the number in your case.
Three Routes to Blood Evidence
| Route | How it works | Source |
|---|---|---|
| Officer-directed draw under implied consent | An officer with probable cause asks hospital staff to draw blood from a driver who has been advised and has not refused, or who is unconscious or incapable of refusal | MCA § 61-8-1016(2), (3) |
| Search warrant | A judge authorizes the draw on a sworn showing of probable cause | MCA §§ 46-5-221, 46-5-224 |
| Investigative subpoena for a medical sample or records | A prosecutor shows a judge probable cause that an offense was committed and that the hospital holds the evidence | MCA §§ 46-4-301(3), 61-8-1019(6) |
Warrants are covered in blood draw warrants. The rest of this page deals with the other two.
How the State Gets a Medical Sample or Records
The implied consent statute says it "does not apply to tests, samples, and analyses of blood, breath, or urine used for purposes of medical treatment or care of an injured motorist" (MCA § 61-8-1016(5)). The next subsection adds that the statute does not prohibit releasing that information for law enforcement purposes as provided in two other laws (§ 61-8-1016(6)).
Those two laws work together. Under MCA § 61-8-1019(6), if an officer has probable cause to believe a person committed DUI and a sample of blood or another bodily substance was taken from that person "for any reason," a portion sufficient for analysis must be provided to an officer if requested for law enforcement purposes "and upon issuance of a subpoena as provided in 46-4-301."
MCA § 46-4-301(3) sets the bar for that subpoena. For constitutionally protected material such as medical records, a judge may issue it only when a prosecutor's affidavit shows a compelling state interest, which requires facts supporting probable cause that an offense has been committed and that the information is in the possession of the person or institution subpoenaed. The health care information statute recognizes such a subpoena as a lawful basis for disclosure (MCA § 50-16-535(1)(k)).
Hesser: What Probable Cause Looks Like
State v. Hesser, 2024 MT 134, involved a motorcyclist found in a ditch in critical condition after leaving a dry, well-paved road on a gradual curve in daylight, with no sign of braking or correction. A trooper learned he had prior DUI convictions and that hospital staff had drawn blood, and asked that the sample not be discarded. Two days later a deputy county attorney obtained an investigative subpoena, and the sample was sent to the State Crime Lab.
The Court upheld the subpoena. It repeated that prior criminal history alone is not enough, but held that the history together with an unexplained, serious single-vehicle crash established probable cause (¶ 13).
The driver pointed out that the affidavit mentioned no odor of alcohol, no admission of drinking, and no open container. The decision shows that a subpoena can rest on circumstances, and also that the affidavit must actually lay them out.
Unconscious or Unable to Refuse
Under MCA § 61-8-1016(3), a person "who is unconscious or who is otherwise in a condition rendering the person incapable of refusal is considered not to have withdrawn the consent" that the statute attributes to every driver. Hesser applied that provision as a second, independent ground. Because the driver was unconscious and intubated after a crash involving serious bodily injury, the Court concluded the trooper "could have lawfully directed medical staff to obtain a blood sample" (¶ 20).
The officer still needs a statutory basis to request the test. After a crash, the relevant ones are probable cause that the person was driving in violation of the DUI statute and was in a crash causing property damage, or probable cause that the person was driving a vehicle involved in a crash resulting in serious bodily injury or death (MCA § 61-8-1016(2)(a)(iii)(B), (C)).
On the federal side, a plurality of the United States Supreme Court concluded in Mitchell v. Wisconsin (2019) that when a driver is unconscious and cannot be given a breath test, the exigent circumstances doctrine generally permits a blood test without a warrant. Montana courts also apply Article II, Section 11 of the Montana Constitution, as the Laroque decision below shows.
Laroque: Conscious, Injured, and Silent
State v. Laroque, 2026 MT 209, decided September 1, 2026, shows the limit. After a fatal head-on collision in Gallatin County, a highway patrol sergeant read the implied consent advisory to the injured driver in her hospital room and asked three times whether she would take a blood test. She did not answer. He directed staff to draw blood without a warrant, and the crime lab reported THC above the legal limit.
The trial court suppressed the result. It found the driver was overwhelmingly non-responsive, that there was no indication she understood the advisory, and no substantial evidence that she "in any meaningful way voluntarily consented to a warrantless blood draw passively or otherwise." The Supreme Court held those findings were not clearly erroneous and affirmed (¶ 27).
Two details limit how far the case reaches. The State argued the driver was conscious and simply failed to withdraw consent. It "never argued the blood draw was permissible under § 61-8-1016(3)" on the basis that she was incapable of refusal (¶ 21). And the Court declined to consider a good faith argument raised for the first time on appeal (¶ 30). The decision is about proof of consent on a particular record, not a general ban on hospital draws.
What to Do If This Was You
- Request your own hospital records. They show when blood was drawn, by whom, and what was ordered.
- Write down what you remember of any conversation with an officer at the hospital, and who else was in the room.
- Ask what each laboratory tested. Our article on the crime lab and toxicology reports explains how to read a report.
- Ask your lawyer to obtain the subpoena or warrant, the supporting affidavit, and any recording of the advisory. The prosecutor must disclose whether an investigative subpoena was executed in the case (MCA § 46-15-322(2)(b)).
If the State obtained blood without meeting the requirements of the route it used, the remedy is a motion to suppress. Our Missoula DUI defense page explains how we approach a case from the start.
This page explains Montana law in general as of the 2025 Montana Code Annotated and Montana Supreme Court decisions through October 9, 2026. It is not legal advice about your specific case.