Every witness is presumed competent to testify under Fed. R. Evid. 601, unless it can be shown that the witness does not have personal knowledge of the matters about which he is to testify, that he does not have the capacity to recall, or that he does not understand the duty to testify truthfully. This rule applies to persons considered to be insane to the same extent that it applies to other persons.
On December 19, 1979, Terrance McKinley, an inmate at Lorton Reformatory in northern Virginia, sustained serious stab wounds from an assault in his cell. Two of McKinley's fellow inmates, Randy Lightly and Clifton McDuffie, were investigated, but only Lightly was formally charged. McDuffie was not indicted by the grand jury because a court appointed psychiatrist found him incompetent to stand trial and criminally insane at the time of the offense. He is presently confined in a mental hospital. On May 22, 1980, Lightly was convicted of assault with intent to commit murder, and sentenced to ten years imprisonment to run consecutively with the sentence he already was serving. Lightly had also been charged with conspiracy to commit murder, but this charge was dropped. Lightly appealed.
Did the district court err in disqualifying McDuffie to testify?
The Court reversed the judgment and remanded the case for a new trial on grounds that, where the treating physician of such witness indicated that he had a sufficient memory, that he understood the oath, and that he could communicate what he saw, the disqualification of the witness was error as he was presumed to be competent to testify and his testimony would have substantially corroborated that of defendant.