Gilbert Treadwell heard the frantic screams of a DeKalb jogger being attacked Tuesday morning only because he was waiting to turn into heavier-than-normal Briarcliff Road traffic. "It was just the timing of it," said Treadwell, who startled a masked and gloved man stabbing Kimellon Tunkle. "As I had to wait there for 30 to 40 seconds, I was able to hear her screams." Tunkle, 54, was attacked by the masked man about 7 a.m. Tuesday while she was exercising on a running track just off Briarcliff, DeKalb County police said. She fought the man off, but he began stabbing her, police said.