Doctors who evaluated Brockman as medical experts for both the government and the defense offered different views of his cognitive abilities and impairment.
Dr. Ryan Darby, a neurologist who evaluated Brockman as an expert witness for the government, testified that he does not have an accurate representation of Brockman's cognitive abilities and that the symptoms Brockman has presented are worse than brain imaging would suggest. Prosecutors noted in a court filing that Darby was "unable to determine if the Defendant is competent to stand trial."
A second government expert witness, Dr. Robert Denney, a neuropsychologist, said he believed Brockman intentionally exaggerated his cognitive impairment to perform poorly on testing, and he "is continuing to exaggerate, and he is competent to stand trial." Brockman's lawyers raised questions about Denney's credibility as a government expert in an unrelated federal case and asked whether he discounted information provided by the defense when he prepared his report for the court.
Dr. Thomas Wisniewski, a neurologist who testified as a defense expert, wrote in an October report that Brockman has "a permanent, progressive and irreversible cognitive impairment that is currently in the moderately severe stage," which "would severely limit his ability to interact with his attorneys to any substantive, sustained degree, or to participate meaningfully in a courtroom trial," according to a court filing.