A defense expert witness testified before DC Superior Court Judge Michael Ryan on July 20 that a murder suspect’s intellectual and developmental disabilities hinder his competency to stand trial.
Dayshawn Nolan, 23, is charged with second-degree murder while armed for his alleged involvement in the death of Antoinette Davis. According to court documents, Nolan reportedly fired a Roman candle firework into Davis’ apartment on the 400 block of 42nd Street, SE, on July 3, 2022, causing a fire that resulted in injuries from which Davis later died. Davis succumbed to her injuries on July 17, 2022.
The hearing centered on whether Nolan is mentally competent to stand trial, meaning whether he can rationally understand court proceedings and assist his attorneys in his defense.
After two evaluations, the defense’s expert witness concluded that Nolan is incompetent to stand trial. The individual is a board-certified clinical neuropsychologist well-versed in criminal investigation psychology, competency examinations, and assessing defendant competencies.
In cross-examination by the prosecution, the expert testified that Nolan demonstrates an “unsophisticated, childlike, and wishful” understanding of the criminal justice system. According to the expert, Nolan can answer simple factual questions but does not show the rational understanding required to stand trial.
The defense’s expert diagnosed Nolan with an intellectual and developmental disability (IDD), attention-deficit/hyperactivity disorder (ADHD), and post-traumatic stress disorder (PTSD), all of which have reportedly resulted in significant impairment of his reading comprehension, reasoning, and ability to process information.
The specialist also said Nolan frequently confused his previous carjacking case with the current murder case and said he has been “very much impaired for all his life.”
The defense witness said courtroom accommodations such as reading documents slowly, explaining legal terminology, or giving him pen and paper to organize his thoughts might “make him feel better,” but would not redeem his competency to stand trial.
During redirect examination, the defense’s expert testified that Nolan’s test results consistently placed him in the first percentile for intellectual functioning. The expert said neuropsychologists generally consider people who score in the fifth percentile and below on the mental competency test to have an IDD.
He also said psychological evaluations from Nolan’s high school, Saint Elizabeths Hospital, and the Department of Behavioral Health (DBH) corroborated an IDD diagnosis. According to the witness, Nolan was not exaggerating his symptoms or malingering, meaning intentionally fabricating or exaggerating symptoms for personal benefit.
When questioned by Judge Ryan, the witness said Nolan’s lifelong intellectual and developmental disability is extremely unlikely to improve through treatment.
The witness further testified that Nolan had attempted to “mask” his impairments in a variety of ways, including by using colloquial phrases such as “roll the dice” or saying you understand something even when you don’t. The expert said this would hinder an individual’s ability to assist their attorney.
The prosecution presented their own expert witness, a clinical psychologist who performed five evaluations on Nolan beginning in May 2025. The expert witness found Nolan incompetent in her May and July evaluations, but found him competent on two dates in October. In April 2026, the expert found Nolan competent again.
In the prosecution’s expert’s October report, she had noted Nolan knew of his charges, but needed education on the difference between first-and-second-degree murder. She had also reviewed the evidence and witnesses of the case with Nolan, which he described as “confusing.”
Nolan’s attorney, Christen Philips, pressed the witness on a notable discrepancy between her April evaluation notes and her official report. The analyst’s report mentioned a discussion with Nolan regarding witnesses, but there was no documentation of it in her notes.
The prosecution’s expert stated that she thought there were multiple instances where Nolan knew the answers to her questions but did not communicate due to exhaustion and irritation with the process. She did not believe Nolan was “feigning” or “malingering” in his responses.
As a result of time constraints, the contested competency hearing is scheduled to continue on July 21.
