Warrantless blood tests
Missouri v. McNeely
In brief
The Supreme Court did not overturn Missouri's judgment; it left that judgment in place.
- Where it stands
- Decided
Decided 5-4 · April 17, 2013 · Opinion by Justice Kennedy
- What it’s about
- The case concerned whether alcohol’s natural disappearance from Tyler McNeely’s bloodstream justified taking his blood without a warrant after a suspected drunk-driving arrest. The Supreme Court agreed with the Missouri Supreme Court’s judgment (affirmed it).
- Who it affects
- The Missouri Supreme Court's judgment remains in effect in McNeely's case.
Summary: written with AI from the case record.
What it's about
The dispute centered on whether alcohol's natural disappearance made it an emergency to take a blood sample without first getting a warrant.
Question presented
Does the Fourth Amendment prevent the taking of a warrantless blood sample under exigent circumstances?
What the Court decided
Holding
The judgment is affirmed. 358 S. W. 3d 65, affirmed.
- Result
- Affirmed
The vote
From the opinions
“A police officer reading this Court’s opinion would have no idea-no idea-what the Fourth Amendment requires of him, once he decides to obtain a blood sample from a drunk driving suspect who has refused a breathalyzer test.”
What's next
The Missouri Supreme Court's judgment remains in effect. No further proceeding is specified.
Documents
Opinions
Audio
Docket activity
New analysis added
AI analysis generated: Case Briefing
New analysis added
AI analysis generated: Impact Analysis
AI analysis generated: Opinion Summary
Show 5 moreShow fewer
AI analysis generated: Decision Record
Case data updated: summary, question_presented, generation_metadata
Case data updated: question_presented, extraction_metadata
Audio Recording added: Oral Arguments - McNeely
Opinion added: McNeely
More questions
- What did Chief Justice Roberts argue about getting a warrant?
- He argued that officers must seek a warrant if there is time to get one before taking blood.
Sources
Primary materials plus reporting. Best-effort analysis: this explainer relies on a mix of primary materials and trusted secondary sources. Official filings and opinions remain authoritative.