 He also concluded that Clark suffered from acute brain damage and chronic impairment of his mental functioning at the time of his confession (apparently as a result of Clark's recent suicide attempt).The psychiatrist testified that Clark's impaired mental condition would have interfered with his ability to make choices in an informed and reasonable manner and would have rendered him more susceptible to pressure or duress from others.The prosecution offered in response the testimony of the officers who interrogated Clark and the testimony of Clark's attending physician, who concluded that, from a medical-neurological standpoint, Clark was capable of making a decision on waiving his rights.