 The Secret Service has acknowledged it denied some requests by Republican presidential nominee Donald Trump's campaign for increased security at his events in the years before an assassination attempt on him at a recent rally. The reversal is likely to be a key focus of a congressional hearing today where Secret Service Director Kimberly Cheadle is expected to appear before lawmakers who have been expressing anger over security lapses that allowed a 20-year-old gunman to climb atop the roof of a nearby building at Trump's rally in Butler, Pennsylvania and fire his weapon. Republican Congressman Mike Turner will be among those questioning Cheadle.