Anyone in this country can possibly be arrested for voilating the laws of each individual state or federal law regardless of age or mental condition.The issue with someone who has been arrested with a diagnosed mental condition is whether under the statute or law that the person who is arrested under had a required mental capacity to have understood what he or she did or did not do at the time the alleged offense happened was wrong.Example: A mentally ill person shoots someone. Defense of insanity plead. Shooter goes to trial, insanity defense asserted. Result: Not guilty by reason of insanity.If the person who is having a psychotic episode has done nothing criminally wrong, a police officer can take the person to a mental health unit for medical assistance for the person's own protection. There would be no "arrest" in this example.