Pittsburgh synagogue attacker has high IQ, problems with social cues, expert says

The man who killed 11 people in a Squirrel Hill synagogue has an IQ in the top 10% but has deficits in some areas of cognitive function, including his brain’s processing speed, recognizing faces and social cues.

Those characteristics, a defense expert said Monday, can be consistent with schizophrenia, a diagnosis that at least two people who evaluated Robert Bowers have made.

“There are executive-function deficits, they’re not consistently observed, they’re rather task-specific,” said Erin David Bigler, who testified Monday, the sixth day of the trial’s death-penalty eligibility phase.

Bigler, who retired from Brigham Young University in 2018 and is an expert in neuropsychology, said that he reviewed the test data, brain imaging and reports provided by both defense and government experts before reaching his conclusions. He did not evaluate the defendant himself.

Bigler spent the entire court day Monday on the witness stand detailing his work. Bowers, 50, of Baldwin, was convicted June 16 of all 63 federal counts against him, including that he killed 11 people who were members of the Tree of Life-Or L’Simcha, Dor Hadash and New Light congregations on Oct. 27, 2018.

Those killed included Rose Mallinger, 97; Bernice Simon, 84, and her husband, Sylvan Simon, 86; brothers David Rosenthal, 54, and Cecil Rosenthal, 59; Dan Stein, 71; Irving Younger, 69; Dr. Jerry Rabinowitz, 66; Joyce Fienberg, 75; Melvin Wax, 87; and Richard Gottfried, 65.

Before the jurors who convicted him can decide whether they think Bowers should be sentenced to the death penalty or life imprisonment, they first must decide whether he is eligible to be considered for capital punishment. Prosecutors hope to convince jurors that Bowers had the intent to kill the victims, a required factor in securing his eligibility.

Defense attorneys have argued that Bowers has schizophrenia and other brain dysfunction that made it impossible for him to form intent.

Throughout much of last week, several defense witnesses testified about mental health problems Bowers has suffered for most of his life. Testimony indicated that, as early as April 2018, as he was suffering from schizophrenic symptoms, the defendant was planning a mass shooting targeting Jewish people based on what experts have called a delusional belief system.

The defense expects to rest its case for this portion of the penalty phase when testimony resumes Wednesday morning. Government prosecutors said they have two rebuttal witnesses whose testimony could take up to one day each.

Bigler, who was at the forefront of the field of neuropsychology, spent decades instructing at the University of Texas and Brigham Young, from which he retired in 2018. He established a brain imaging laboratory at the Utah university in 1990.

Like other expert witnesses who testified for the defense last week, Bigler confirmed Monday that schizophrenia is not diagnosed through scans and tests, but rather by a clinician who can use those images and test results as factors when reaching a conclusion.

In reviewing Bowers’ test data, Bigler said that the defendant has an IQ of 120, which he said is considered to be “superior,” and ranks him in the 91st percentile.

But relative to his brain’s processing speed, which allows a person to understand and react to information, the defendant tested in the 18th percentile.

“This is telling you that an element of processing speed in Mr. Bowers’ brain isn’t working quite the way that it should,” Bigler said.

Processing speed, he said, is dependent on the integrity of white matter in the brain.

Experts who testified last week said they found a large number of “white-matter hyperintensities,” or lesions, in the defendant’s brain.

While there is a correlation with schizophrenia, Bigler and others said the lesions can also be caused by things such as smoking, which Bowers did for 30 years, the government said.

During his testimony, conducted by video conferencing, Bigler frequently referenced a bright pink, 3-D model of the left hemisphere of Bowers’ brain. He also referenced a PET scan, MRI and EEG done on Bowers’ brain, as well as a number of assessment tests.

In one that examines social cognition, or the ability to read social cues and understand emotion in speech, Bigler said he saw impairment.

Bowers tested in the first percentile, he testified.

In another test, Bowers scored in the fifth percentile for remembering faces, which is typically controlled by the temporal lobe of the brain, which showed structural abnormalities in the various imaging studies conducted, Bigler said.

“For the individual, it creates inefficiencies in their cognitive skills and abilities” that can translate into the real world, he testified.

In another study that involves sorting a deck of cards, the witness said, Bowers performed poorly — only completing two out of six possible sorts.

That can indicate a problem in the frontal lobe.

“My conclusion would be these are executive-system impairments,” Bigler said.

But in other cognitive tests examining the same functions and others, Bowers did just fine, he said.

“Academic ability, as with intellectual ability … tend to get set early in life,” he said.

On cross-examination, U.S. Attorney Eric Olshan focused on how Bigler conducted his review.

The witness admitted that the entirety of his work relied on Bowers’ defense attorneys telling him that their client had a clinical diagnosis of schizophrenia.

“I was to review the neurophysiological testing from the perspective of what would be expected of someone with a clinical diagnosis of schizophrenia,” Bigler said.

“You accepted that as true — that the defendant had a working diagnosis of schizophrenia?” Olshan asked.

“Yes,” Bigler answered.

He could not specify what, if any physician, had made that diagnosis.

Olshan also questioned whether the defendant’s symptoms are exclusive to schizophrenia.

Bigler said they are not and could be indicative of another type of illness.

“A different brain condition, yes,” he answered.

Despite the deficits, Olshan pointed out, Bowers was able to complete fairly complex math problems and spell and pronounce long, complicated words.

Bigler, like other defense experts, said he was not offering any opinion on whether he thought Bowers was able to form intent to kill.

“That is not my role whatsoever in this case,” he said, “and I have not been asked to express my opinion in any way.”