"Truth serum" is in the spotlight in the trial of James Holmes, the 25-year-old accused of killing 12 people and wounding dozens more in a shooting rampage inside an Aurora, Colo. movie theater last July.
Holmes' attorney told a court Tuesday that he was not ready to enter a plea, but the judge entered a not guilty plea for him and said he could later change the plea to not guilty by reason of insanity.
Had Holmes plead guilty by reason of insanity, he would be examined by doctors at a state mental hospital and could be given "truth serum" under court order to determine whether he was legally insane, according to
The process is known as a "narcoanalytic interview," and it occurs when patients are given drugs to lower their inhibition.
But will the drugs actually get people to tell the truth?
Dr. Michael Aronoff, a clinical professor of psychiatry and attending psychiatrist at Lenox Hill Hospital in New York City, expressed his doubts.
"Insanity is a legal defense, it is not a medical diagnosis," he told CBSNews.com. "Therefore, if you're using a medical procedure to try and establish a legal criterion, it's not going to work."
Doctors or law enforcement try to use a truth serum to get a person to share a desired piece of information. Classically, substances like sodium amytal and sodium thiopental (Pentothal) were the substances of choice.
Aronoff said when you give a person a drug that depresses the brain and central nervous system -- even alcohol -- it may lead to decreases in judgement and critical thinking. The aim in this state is to get people to let their inhibitions down and reveal something they were either trying to hide or something that they may not even realize they knew.
But, just because you're inhibiting or suppressing a person's state with drugs doesn't mean what's coming out is truthful, he said. What could happen is the drugs can free up "word salad" -- a mishmash of thoughts and impressions that are brought to the surface. Aronoff, who has a background in forensic psychiatry, says there is no definitive scientific evidence that shows giving these medications is a reliable way of evaluating the truth.
"There are no reliable lie detectors.," he said. "None"
What's more, Aronoff argued this inhibited state could make a person more vulnerable to inadvertent suggestion or manipulation, which can lead to cases of "false memory syndrome," in which therapists plant seeds that present as memories once the patient is fully recovered.
Some pieces of information may be truthful, others may be complete nonsense that are given under duress to try to please the people around them, he said.
"They might spill some beans, but you don't know what those beans are," said Aronoff.
Other experts outside of medicine agreed truth serum is infrequently used.
"If a defendant loses his right to remain silent because the court has authorized the use of drugs that make him talk, that would raise all sorts of fifth amendment issues that both sides would have to address," William Shepherd, chair of the criminal justice section of the American Bar Association, told The Guardian. He said use of a truth drug was highly unusual in the United States.
Karen Steinhauser, a former prosecutor who is a law professor at the University of Denver and a defense attorney, said she could not find any case law about use of the narcoanalytic interview, though the technique is allowed by Colo. law.
"It comes up so rarely," she said, telling the Associated Press she knows nothing about it.