The man who rammed a car into two officers at a barricade outside the U.S. Capitol, killing one of them before he was shot to death by police, had been suffering from delusions, paranoia and suicidal thoughts, a U.S. official told The Associated Press on Saturday. Investigators believe it was an isolated incident from a disturbed young man. ... Investigators are increasingly focused on Green's mental health as they work to identify any motive for the attack, said the official, who was not authorized to speak publicly about an ongoing investigation and spoke to The AP on condition of anonymity....