Kahler v. Kansas
In brief
Kansas may keep its rule: the Supreme Court said the Constitution does not require an insanity defense based on inability to recognize moral wrongness.
- Where it stands
- Decided
Decided 6-3 · March 23, 2020 · Opinion by Justice Kagan
- What it’s about
- This case asked whether Kansas could limit the insanity defense so that mental illness could negate criminal intent, but could not excuse a defendant who understood what he was doing yet could not tell right from wrong.
- Who it affects
- The decision leaves Kansas's approach in place. It says the Constitution does not require the state to excuse a defendant who, because of mental illness, could not recognize that the crime was morally wrong.
Summary: written with AI from the case record.
What it's about
The Supreme Court upheld Kansas’s law, ruling that the Constitution does not require states to adopt a traditional moral-capacity insanity defense.
The case tested how much freedom states have to decide when mental illness excuses criminal responsibility.
Question presented
Do the Eighth and Fourteenth Amendments permit a state to abolish the insanity defense?
What the Court decided
Holding
Due process does not require Kansas to adopt an insanity test that turns on a defendant’s ability to recognize that his crime was morally wrong. 307 Kan. 374, 410 P. 3d 105, affirmed.
- Result
- Affirmed
The vote
From the opinions
“But here, Kansas has not simply redefined the insanity defense.”
What's next
The Supreme Court's review is complete, and the Kansas Supreme Court's ruling remains in place.
Documents
Docket activity
New analysis added
AI analysis generated: Case Briefing
AI analysis generated: Decision Record
Opinion added: opinion
Brief added: Petition
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Court Order added: Lower Court Orders/Opinions
Brief added: Questions Presented
More questions
- What did Kahler v. Kansas decide?
- The Supreme Court upheld Kansas's ruling and said due process (constitutional fairness) does not require an insanity defense for not knowing right from wrong.
- How did Kansas's rule treat mental illness?
- It could remove criminal intent, but it did not excuse someone who understood the act yet could not tell right from wrong.
- Who wrote the Court's opinion in Kahler v. Kansas?
- Justice Kagan wrote the opinion, signed by Chief Justice Roberts and Justices Thomas, Alito, Gorsuch, and Kavanaugh. Justice Breyer disagreed in a separate opinion, signed by Justices Ginsburg and Sotomayor.
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.