This educational guide is based on the linked primary sources. It is not a Court publication, is not affiliated with the Court, and is not legal advice.
In brief
Overview
According to Petitioner, the case concerns the constitutional sufficiency of California's catchall factor (k) instruction used in the penalty phase of capital cases.
According to Petitioner, the factor (k) instruction recites California Penal Code §190.3.
According to Petitioner, in California, jurors are told that during the penalty phase their sole concern is to choose between death and life without parole.
The petitioner argues that the factor (k) instruction would foreclose consideration of present good‑character evidence, including evidence from Boyde and Payton.
Background and question before the Court
Justice Stevens asked whether facts that occurred before the crime differ from facts that might have occurred after the crime.
Justice Kennedy asked how post‑crime prison conduct reduces the seriousness of a previous crime.
Justice Ginsburg inquired about the source of factor (k), asking whether it derives from a model code and how many other states have similar instructions.
Justice Ginsburg asked for clarification of the petitioner’s brief, noting that the challenge to factor (k) was limited to the exclusion of Skipper evidence in that particular case.
What each side argues
Petitioner (ROBERT L. AYERS, JR. ACTING WARDEN)
The petitioner contends that the factor (k) instruction is constitutionally sufficient because it follows the statutory language of Penal Code §190.3.
According to Petitioner, the petitioner asserts that the instruction would prevent the jury from considering any present good‑character evidence, such as evidence from Boyde and Payton.
According to Petitioner, the petitioner emphasizes that jurors are instructed that their only decision in the penalty phase is between death and life without parole.
What happened at oral argument
During oral argument, Justices Stevens, Kennedy, and Ginsburg posed questions concerning the timing of facts relative to the crime, the effect of post‑crime conduct, and the origins and prevalence of the factor (k) instruction.
According to Justice Souter, justice Souter noted that the prosecutor would have answered Justice Stevens’s question in the opposite way.
What the Court decided
Why it matters
Terms to know
No glossary terms are available for this guide.
Primary sources
Read the source materials on the official site or open the immutable repository copy used for this guide.
- 8cbb8227f053458ac9f5-r1-359c1a228a56a793.pdforal argument transcript
Guide generated September 21, 2026. Automated validation accepted this version.