WOODLAND, Calif. — Defense expert witnesses testified this week in the retrial of Carlos Reales Dominguez that he was experiencing schizophrenia, not cannabis-induced psychosis, at the time of the 2023 Davis stabbing incidents, as testimony focused on whether severe mental illness explains his mental state during the charged offenses.
Dominguez is being retried on two counts of second-degree murder and one count of attempted murder following a mistrial last year. He is charged in connection with the 2023 Davis stabbing incidents, including the killings of David Breaux and Karim Abou Najm and the attempted murder of Kimberly Guillory. His mental state at the time of the alleged offenses has become a central issue in the case.
Deputy Public Defender Daniel Hutchinson first called forensic psychiatrist Dr. Sarah Vinson to testify about her independent evaluation of Dominguez.
Before discussing Dominguez directly, Hutchinson questioned Dr. Vinson about her education and professional background. The court qualified Dr. Vinson as an expert in psychiatry after she testified about her experience with schizophrenia, severe mental illness, substance use disorders and substance-induced psychotic disorders.
Dr. Vinson said she became involved in the Dominguez case after being contacted by the public defender’s office. She was retained to conduct an independent evaluation related to Dominguez’s plea of not guilty by reason of insanity.
She said she reviewed a large volume of material, including jail medical records, Atascadero State Hospital records, emergency room records, high school and UC Davis records, prior expert reports, prior testimony, police interrogation videos, body camera footage and recordings of Dominguez in custody.
Dr. Vinson also interviewed Dominguez at the jail in August 2024 for about three hours. She said the interview included questions about his background, family history, childhood in El Salvador, immigration experience and symptoms of mental illness.
When asked whether she had an opinion about Dominguez’s current mental illness, Dr. Vinson testified that he suffers from schizophrenia. She also testified that, in her opinion, he had schizophrenia at the time of the charged offenses in April and May 2023.
Dr. Vinson described the period of the stabbings as Dominguez’s “first break.” She explained that a first break occurs when symptoms of psychosis become severe enough that the person’s connection to reality is significantly impaired.
She explained that schizophrenia can involve positive symptoms, such as hallucinations, delusions and disorganized thinking, as well as negative symptoms, such as reduced speech, flat affect, lack of motivation and social withdrawal.
Dr. Vinson said that when she met with Dominguez in 2024, he had already been taking antipsychotic medication for more than a year. She said she did not observe active hallucinations or delusions during that interview, but she did observe negative symptoms.
She said it is common for antipsychotic medication to improve hallucinations or delusions while leaving negative symptoms behind.
Dr. Vinson also testified that she saw no evidence that Dominguez was malingering, meaning exaggerating or creating symptoms for outside gain. Instead, she said she saw “under-reporting,” explaining that Dominguez did not appear to fully understand his own illness or its impact.
A large portion of the testimony focused on Dominguez’s childhood and possible trauma. Dr. Vinson discussed the stress-diathesis model, which she described as the idea that mental illness can develop through a combination of genetic vulnerability and life stressors.
Hutchinson asked Dr. Vinson to assume facts regarding the physical discipline Dominguez endured from his father, including being hit with a belt, forced to kneel on rice while holding books and made to stand naked outside on a cold night. Dr. Vinson testified that those circumstances would constitute abuse by a parent.
Dr. Vinson also discussed immigration-related stress. She testified that fear connected to immigration status can affect a person’s willingness to seek mental health care or interact with authority figures.
The defense then turned to Dominguez’s police interrogation. Dr. Vinson said she observed confusion, lack of gestures, difficulty with speech and difficulty following questions during the interrogation.
She described Dominguez as “remarkably still,” saying that he barely moved during the seven-hour interview.
Dr. Vinson said Dominguez’s young age, mental health symptoms and lifelong fear tied to immigration status could all make him more vulnerable in that setting.
Hutchinson also asked Dr. Vinson about several incorrect answers Dominguez gave during the interrogation, including the wrong birth date, a misspelled version of his mother’s name, a wrong address and a false name. Dr. Vinson testified that those inconsistencies were evidence of a disorganized mind, which she said is consistent with schizophrenia.
She also pointed to moments where Dominguez seemed disconnected from the seriousness of the situation. Dr. Vinson said it was unusual that, after hours of questioning about homicides and an attempted homicide, Dominguez asked what time it was because he believed he needed to study for a test.
“If he was connected to reality, that wouldn’t have been the first thing on his mind,” Dr. Vinson said.
Dr. Vinson also acknowledged that she considered whether Dominguez may have had a cannabis-induced psychotic disorder. However, she concluded his condition was schizophrenia.
She explained that Dominguez continued to show symptoms in custody long after his last use of cannabis. She said his symptoms persisted and even worsened in jail, which led her to conclude the case was “not just about cannabis.”
Dr. Vinson also responded to opinions from Dr. Zachary Torrey, another expert in the case, who had accused her of confirmation bias. Dr. Vinson defined confirmation bias as starting with a conclusion and then looking only for evidence that supports it.
She rejected the accusation, responding that multiple clinicians had independently concluded that Dominguez had a primary psychotic disorder.
“Clinician after clinician and setting after setting said that this young man had a primary psychotic disorder,” Dr. Vinson testified, describing it as a “convergence of opinions.”
By the end of direct examination, Dr. Vinson testified that, in her opinion, Dominguez was in a state of florid psychosis at the time of the charged offenses. She said he was experiencing positive symptoms of schizophrenia, including hallucinations and delusions, and that those symptoms substantially affected his thought process and perception of reality.
The retrial reconvened Friday with Hutchinson conducting a redirect examination of psychiatrist Dr. Stephen Weiner, who was commissioned to conduct an independent psychiatric evaluation of Dominguez’s mental state.
Hutchinson argued that Deputy District Attorney Matt De Moura’s previous cross-examination omitted a portion of Dr. Weiner’s report that, according to the defense, provided important context.
“If you do not read them together, could it result in a false or misleading impression as to what Mr. Dominguez actually said?” Hutchinson asked.
According to Dr. Weiner, De Moura’s line of questioning created “an incomplete record because the final paragraph and the context in it were excluded.”
Hutchinson then asked Dr. Weiner what he had included in the final paragraph of his report.
Dr. Weiner testified that, according to Dominguez’s account during the evaluation, he had been unable to recognize any of the victims as human beings during the offenses and instead perceived only shadows or shadow figures, stating he was scared because he “didn’t want to hurt any human being.”
Hutchinson continued questioning Dr. Weiner regarding Dominguez’s mental state and hallucinations. Dr. Weiner explained that Dominguez continued hallucinating shadows several months after entering custody, which he said was inconsistent with cannabis-induced psychosis.
De Moura questioned Dr. Weiner on the impact cannabis use can have on schizophrenia, emphasizing that Dominguez “was smoking approximately three grams of cannabis every two days.”
“The relationship between cannabis and schizophrenia is complex, and the way it’s currently being phrased is vague,” Dr. Weiner responded.
During recross-examination, De Moura used the term “florid psychosis” interchangeably with “schizophrenia.” Dr. Weiner responded that “florid psychosis” is not a diagnosis included in the Diagnostic and Statistical Manual of Mental Disorders, nor had it previously been defined by the court.
Dr. Weiner testified that Dominguez had been diagnosed with schizophrenia and that the illness was present at the time of the alleged offenses.
“Evidence for [Dominguez] having schizophrenia is well established,” Dr. Weiner stated.
Dr. Weiner maintained that schizophrenia, rather than cannabis, provided the best explanation for Dominguez’s mental state at the time of the alleged offenses, despite the “incomplete record” created by the omission of the final paragraph of his report during cross-examination.
The retrial is scheduled to resume July 13 at 9 a.m.
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