A murder defendant may present expert testimony regarding battered women's syndrome. A California Appeals Court limited the expert's testimony to that of establishing that an abusive background was responsible for the defendant's subjective perception. Opinion evidence regarding the defendant's state of mind at the time the crime was committed was properly excluded.

Deborah Erickson was charged for the murder of her repeatedly abusive live-in boyfriend. At her trial for murder, the court refused to admit expert testimony that she feared for her life at the time Pruitt was killed. However, a general opinion about battered women's syndrome was allowed.

On appeal, she argued that the trial court erred by refusing to permit testimony concerning her mental state on the night of the crime. She contended that previous case law disallowing such testimony was abrogated by the subsequent enactment of Evidence Code Section 1107(a), which stated in part, "In the guilt phase of a criminal action, any expert testifying about a defendant's mental illness, mental disorder, or mental defect shall not testify as to whether the defendant had or did not have the required mental states, which includes malice aforethought. . . ."

The Appeals Court rejected her argument, holding that the statute's use of the phrase "victims of domestic violence" suggested a reference to victims as a class, not to the victim of domestic violence in any particular case before the court. "Such a class-oriented construction is fully consistent with the traditional purpose for admission of 'syndrome' evidence," wrote the Court. "The Legislature did not intend to permit use of battered women's syndrome to predict the actual state of mind of a particular individual at a given moment." The trial court's decision to exclude the testimony about the effect of battered women's syndrome upon the defendant's state of mind was affirmed and the conviction was upheld.