On the morning of Sept. 15, at around 5:30 a.m., Williams was running on the north side of the trail. He heard screams from a woman, pointed his flashlight in the direction of them and said he realized that she was being sexually assaulted.
The crime was one of three similar incidents in a several week period that put runners' on edge along the busy path.
"I came up, pulled my gun and told him to get off of her," he said. "Get on your knees and show me your hands."