CALIFORNIA LEGISLATURE— 2019–2020 REGULAR SESSION

Senate Bill
No. 938

Introduced by Senator Wiener

February 06, 2020

An act to amend Section 802 of the Evidence Code, and to amend Section 1473 of the Penal Code, relating to trial testimony.


LEGISLATIVE COUNSEL'S DIGEST


SB 938, as introduced, Wiener. Trial testimony: expert witnesses: writ of habeas corpus.
(1) Existing law allows a person who is unlawfully imprisoned or restrained of their liberty to prosecute a writ of habeas corpus to inquire into the cause of their imprisonment or restraint. Existing law allows a writ of habeas corpus to be prosecuted on the basis of false evidence that is substantially material or probative to the issue of guilt or punishment that was introduced at trial. Existing law defines false evidence for these purposes as including the opinions of experts that have been repudiated by the expert or that have been undermined by later scientific research or technological advances.
This bill would expand the definition of false evidence to include the opinions of experts that are undermined by scientific research that existed at the time of the expert’s testimony and opinions for which a reasonable dispute has emerged within the expert’s relevant scientific community as to the validity of the methods or theories upon which the expert based their opinion.
(2) Existing law limits the testimony of a witness who is testifying as an expert to matter that is of a type that reasonably may be relied upon by an expert in forming an opinion upon the subject to which the expert’s testimony relates. Existing law allows a witness testifying in the form of an opinion to state on direct examination the reasons for their opinion and the matter upon which it is based.
This bill would specify that an expert opinion based on circular reasoning is not based on matter that is of a type that reasonably may be relied upon by an expert in forming an opinion upon a subject. The bill would define circular reasoning as referring to any portion of an expert’s opinion that is solely based upon the premise that the expert seeks to conclude, including any portion of the opinion or testimony that is based upon studies, literature, data, or other materials on which the expert relies that accepts the same unproven premise that the studies, literature, data, or other materials on which the expert relies seeks to conclude.
Vote: MAJORITY   Appropriation: NO   Fiscal Committee: YES   Local Program: NO  

The people of the State of California do enact as follows:


SECTION 1.

 Section 802 of the Evidence Code is amended to read:

802.
 (a) A witness testifying in the form of an opinion may state on direct examination the reasons for his their opinion and the matter (including, in the case of an expert, his special knowledge, skill, experience, training, and education) upon which it is based, unless he is they are precluded by law from using such those reasons or that matter as a basis for his their opinion. In the case of an expert, this includes the expert’s special knowledge, skill, experience, training, and education. An expert opinion based on circular reasoning is not based on matter that is a type that reasonably may be relied upon by an expert in forming an opinion upon a subject to which the expert’s testimony relates. The court in its discretion may require that a witness before testifying in the form of an opinion be first examined concerning the matter upon which his their opinion is based.
(b) For purposes of this article, “circular reasoning” refers to any portion of an expert’s opinion that is solely based upon the premise that the expert seeks to conclude. It also includes any portion of the opinion or testimony that is based upon studies, literature, data, or other materials on which the expert relies that accepts the same unproven premise that the studies, literature, data, or other materials on which the expert relies seeks to conclude.

SEC. 2.

 Section 1473 of the Penal Code is amended to read:

1473.
 (a) A person unlawfully imprisoned or restrained of his or her their liberty, under any pretense, may prosecute a writ of habeas corpus to inquire into the cause of his or her their imprisonment or restraint.
(b) A writ of habeas corpus may be prosecuted for, but not limited to, the following reasons:
(1) False evidence that is substantially material or probative on the issue of guilt or punishment was introduced against a person at a hearing or trial relating to his or her their incarceration.
(2) False physical evidence, believed by a person to be factual, probative, or material on the issue of guilt, which was known by the person at the time of entering a plea of guilty, which was a material factor directly related to the plea of guilty by the person.
(3) (A) New evidence exists that is credible, material, presented without substantial delay, and of such decisive force and value that it would have more likely than not changed the outcome at trial.
(B) For purposes of this section, “new evidence” means evidence that has been discovered after trial, that could not have been discovered prior to trial by the exercise of due diligence, and is admissible and not merely cumulative, corroborative, collateral, or impeaching.
(c) Any allegation that the prosecution knew or should have known of the false nature of the evidence referred to in paragraphs (1) and (2) of subdivision (b) is immaterial to the prosecution of a writ of habeas corpus brought pursuant to paragraph (1) or (2) of subdivision (b).
(d) This section does not limit the grounds for which a writ of habeas corpus may be prosecuted or preclude the use of any other remedies.
(e) (1) For purposes of this section, “false evidence” includes opinions of experts that have either been repudiated by the expert who originally provided the opinion at a hearing or trial or that have been undermined by later scientific research or technological advances. scientific research, including scientific research that existed at the time the expert’s testimony was given, technological advances, or the emergence of a reasonable dispute within the expert’s relevant scientific community as to the validity of the methods or theories upon which the expert based their opinion.
(2) This section does not create additional liabilities, beyond those already recognized, for an expert who repudiates his or her their original opinion provided at a hearing or trial or whose opinion has been undermined by later scientific research or research, technological advancements. advancements, or the emergence of a reasonable dispute within the expert’s relevant scientific community as to the validity of the methods or theories upon which the expert based their opinion.