Judge oks truth serum for alleged Colarado gunman, James Holmes James Holmes may be required to undergo an interview using truth serum unless he pleads guilty. IF the gunman allegedly behind the Colarado theatre shooting does not plead guilty to the massacre, he could be given truth serum to determine whether he is insane. James Holmes is charged with killing 12 people and injuring seven at a midnight screening of The Dark Knight. He is scheduled to enter a plea today to multiple counts of murder and attempted murder. District Judge William Sylvester, who is overseeing the case, said Holmes could be given the serum to determine whether he was legally insane at the time of the shootings on July 20. The drug - usually a solution of sodium amytal and pentothal - is designed to lower the inhibition of the patient and is used during a "narcoanalytic interview" (an interview that is conducted while the patient is experiencing the effects of the serum). If he pleads not guilty by reason of insanity doctors at the state mental hospital would be required to examine him. However Judge Sylvester did not specify what kind of drugs should be used but said the examination should include ones that are "medically appropriate." He also said Holmes should be given a polygraph test. Holmes' lawyers objected to the order, arguing that a narcoanalytic interview and polygraph violates his rights. Judge Sylvester said he took the suggestions of both the defence and prosecution into account however he did not address the defence's objections to the truth serum and polygraph.