DENTON A North Texas sheriff who criticized the left and political correctness in a Facebook post after Mondays terror attack in Manchester, England, defended his comments Tuesday. I stand behind it, Denton County Sheriff Tracy Murphree told NBC 5. We need to be realistic about the world we live in. The Manchester bombing, which happened at the end of an Ariana Grande concert, left at least 22 dead, including an 8-year-old girl.