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Pen. Code, § 28 · Title 1. OF PERSONS LIABLE TO PUNISHMENT FOR CRIME

Pen. Code, § 28

Verbatim from the official edition

Text — As published in the Legislative Counsel's database, tables dated October 18, 2026 (pubinfo_2025.zip)

(a) Evidence of mental disease, mental defect, or mental disorder shall not be admitted to show or negate the capacity to form any mental state, including, but not limited to, purpose, intent, knowledge, premeditation, deliberation, or malice aforethought, with which the accused committed the act. Evidence of mental disease, mental defect, or mental disorder is admissible solely on the issue of whether or not the accused actually formed a required specific intent, premeditated, deliberated, or harbored malice aforethought, when a specific intent crime is charged.

(b) As a matter of public policy there shall be no defense of diminished capacity, diminished responsibility, or irresistible impulse in a criminal action or juvenile adjudication hearing.

(c) This section shall not be applicable to an insanity hearing pursuant to Section 1026.

(d) Nothing in this section shall limit a court’s discretion, pursuant to the Evidence Code, to exclude psychiatric or psychological evidence on whether the accused had a mental disease, mental defect, or mental disorder at the time of the alleged offense.

Notes and commentary — not statutory text

History

Amended by Stats. 2002, Ch. 784, Sec. 528. Effective January 1, 2003.

Source of truth

Edition
As published in the Legislative Counsel's database, tables dated October 18, 2026 (pubinfo_2025.zip)
Official file
https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=PEN&sectionNum=28.
Text hash
sha256 8c89fa63269f071fb5c474aa8cc6f923b729c6f50472c9c00e1a919130c3c976
Composed by
compose_ca.py 2026-10-22: the Legislative Counsel's CAML content files read by a tokenizer (caml_readers.reader_a); an independent xml.etree reading (caml_readers.reader_b) agrees on every section

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