A mother's heart was broken two days after the funeral of her police officer son, who was gunned down in the Las Vegas massacre. Sheryl Stiles, 56, suffered cardiac arrest while riding an escalator, authorities said. She fell down the moving steps, hitting her head and causing extensive brain damage, her family said. She had traveled from Louisville, Kentucky, for the funeral of officer Charleston Hartfield. InsideEdition.com's Leigh Scheps (http://twitter.com/LeighTVReporter) has more.