The prosecution used the testimony of Bridgewater State Hospital psychologist Joel Haycock, who spent eleven days with Salvi out of his sixty days under observation. Haycock determined that during the time of his observation of Salvi in a hospital setting, Salvi had no hallucinations, could speak in a non-digressive linear way, and was capable of understanding guilt. Haycock observed no signs of psychotic disorder during his time with Salvi. Haycock also asserted that Salvi had no mental disease at the time of the crime and was competent to stand trial.