Derek Hubbard of La Joya High School. Hubbard ran a blazing 4.36 40, which not only won him the Fastest Man Award, but also made him the fastest freshman of all-time at the National Underclassmen Combine. Hubbard, 5-foot-5 and 139-pounds, also had a 29-inch vertical, 9'5" broad, and 4.62 shuttle.

National Frosh Soph High School Football Combine Camp

Scroll down the page a little to read about him. He's got a highlight tape on youtube, but I imagine its against freshmen competition.