The email came in the dead of winter and was chilling indeed. A man calling himself Abdul Yohanish said he was about to bomb the major local bridges connecting Ohio to Kentucky, the local international airport, and Paul Brown Stadium, home of the Cincinnati Bengals. Just who was Abdul Yohanish? And was the threat real? FBI agents used all their traditional resources in their race against time to find the answers. But they also used a new tool, a forensic lab of sorts, but for computers. It’s the latest entry in a rapidly developing and ever-changing field of police work called digital forensics…