As far-fetched as it sounds, systems that aim to get inside an evildoer's head are among the proposals floated by security experts thinking beyond the X-ray machines and metal detectors used on millions of passengers and bags each year.

Paul Newman never much cared for what he once called the "rubbish" of Hollywood, choosing to live in a quiet community on the opposite corner of the U.S. map, staying with his wife of many years and - long after he became bored with acting -...