Faulkner County Prosecutor H.G. Foster, however, says Chauncey should still be held responsible for his actions.
Chauncey was charged along with his half brother, Richard Francis Barr III, 21, of Berkeley Springs, W.Va., with murder, rape and kidnapping.
Barr was convicted in October in Faulkner County Circuit Court of 16 felony charges, including attempted capital murder and accomplice to rape, in connection with attacks and abductions involving three women at Conway on Feb. 11. Chauncey's trial is slated for Jan. 20.
The two men also are charged with capital murder in the slaying of a Sheridan truck driver near Morrilton on Jan. 31. And, at Memphis, Tenn., Chauncey is charged with raping a woman.
A wide debate is under way among authorities in the fields of law and psychology about whether Chauncey or others like him should end up in prison or in a mental hospital.
Elyn Saks, a professor of psychiatry at the University of California Medical Center, said she believes that, if an alternate personality commits a crime without the main personality's knowledge or consent, the defendant should not be convicted of the crime but should receive treatment.
Courts have taken two approaches to the issue, she said. One is to look at whether the alternate personality meets the requirements of the insanity defense, she said. The other is to determine whether the host personality participated in the crime, she said.
But Stephen H. Behnke, an instructor of psychiatry at Harvard University, said he believes it is irrelevant whether one personality knew about the crime. He defines multiple personalities as different mental states, as opposed to different people.
"The law should examine whether, at the time of the crime, this person was able to understand or appreciate whether what he was doing was wrong, and whether he was able to conform his actions to the requirements of the law," he wrote.
"If, at the time of the act, the persona did have these capacities, then the presence of other mental states, identities or personalities within him is irrelevant to the question of criminal responsibility."
Simon declined in his evaluation to offer an opinion on whether Chauncey is sane.
While experts disagree on whether a person with the disorder is responsible for crimes, they tend to agree about how a person acquires the disorder.
"It is usually the result of early childhood trauma," said Todd Burke, an associate professor of criminal justice at Radford University who has studied the disorder.
When a person suffers a trauma. a separate identity is formed as a way of coping with the situation, Burke said.
In Saks' words, "It's no longer 'me' that's being abused; it's 'John Doe' that's being abused. They don't have to deal with it anymore."
In the Chauncey case, Simon wrote that Chauncey does not recall the crimes he is accused of committing. Simon also noted in his written evaluation that Chauncey had complained of headaches and an inability to account for some periods of his life.
There also is evidence that he suffered abuse as a child, Simon wrote.
In the last decade, the State Hospital has diagnosed only about 10 people with the disorder, Simon said. The diagnosis in a few of those cases resulted in judges dismissing the charges and sentencing the defendants to treatment, he said.