Roberts writes in Heien that the Fourth Amendment tolerates only objectively reasonable mistakes of fact or law
John G. Roberts Jr.Chief justice, writing the Court's majority opinion
Roberts defends treating objectively reasonable legal mistakes like reasonable factual mistakes.
Responding to
An objectively reasonable mistake of substantive law can justify a traffic stop under the Fourth Amendment.
“The Fourth Amendment tolerates only reasonable mistakes, and those mistakes—whether of fact or of law—must be objectively reasonable.”
Original text
Where this statement fits
Heien: Roberts and Sotomayor split over traffic stops based on mistakes of law
The Supreme Court held in 2014 that an objectively reasonable mistake of law can justify a traffic stop. Chief Justice John Roberts defends that rule. Justice Sonia Sotomayor argues that police should be judged against the law as it actually exists.
Source and context
Original text
About this source
The full opinions set out the disagreement over whether an objectively reasonable mistake of substantive law can justify a traffic stop.
Archived copy (opens in a new tab)Before the quotation
The majority considers whether an officer's mistaken reading of a brake-light statute can support reasonable suspicion.
After the quotation
Roberts limits the rule to objective reasonableness and rejects an advantage from sloppy study of the law.
How this statement is classified
The label describes this statement's response within the context above.
Why this label?
He supports allowing the stop on this basis, the conduct and rule at issue.
- Recorded on
- Published here
More from this case
Read the full caseSotomayor opposes traffic stops based on mistakes of law
“Departing from this tradition means further eroding the Fourth Amendment's protection of civil liberties in a context where that protection has already been worn down.”Read statement
Share or embed this statement
The embed keeps its attribution link to The Dispute Index. Credit the image to The Dispute Index and link to the statement page.
Cite this record
- Publisher
- The Dispute Index
- Title
- Roberts writes in Heien that the Fourth Amendment tolerates only objectively reasonable mistakes of fact or law
- First published
- Last updated
- Permalink
- https://disputeindex.com/events/6453-roberts-defends-treating-objectively-reasonable-legal-mistakes-like
Last updated marks the most recent saved version of this published statement.
The Dispute Index. "Roberts writes in Heien that the Fourth Amendment tolerates only objectively reasonable mistakes of fact or law". First published: 2026-10-22. Last updated: 2026-10-23. https://disputeindex.com/events/6453-roberts-defends-treating-objectively-reasonable-legal-mistakes-like