Heart-pounding surveillance footage shows three heroic civilians firing back at Idaho In-N-Out gunman Chad Williams – helping to stop the mass shooter from carrying out more carnage. 4 An off-duty state trooper exchanged gunfire with Chad Williams at one point during the horror rampage, the surveillance footage shows. Twin Falls PDWilliams’ car then creeps forward a few feet before he emerges with a black handgun and walks toward the drive-thru’s second window. That’s when former Twin Falls and Idaho State Police Officer Austin “AJ” Scott starts running toward the gunman, the pulse-racing video shows. Twin Falls PDBut “due to [Scott’s] severe injury and blood loss, he is pulled back into his vehicle before going to the hospital,” the narrator explains.