I'm not familiar with him. Here's what ESPN says. Not so great:
SELECTED BY DALLAS , ROUND 4, PICK 25, OVERALL PICK 121
CB | (5'10", 197, 4.5) | GEORGIA | COLLEGE STATS
Data from Scouts, Inc.
Comments: Thornton is at his best in zone coverage when he can give a cushion and keep everything in front. Long arms, knocks down passes underneath. Good recognition, gets good break on balls in zone. Quick, agile. Good burst out of pedal. No special qualities. Not physical in coverage. Gets pushed around. Does not fill as hard as he should vs. run, has trouble getting off blocks. Lacks smooth hips, top-end speed to match up vertically one-on-one. Lacks ball skills, doesn't make enough big plays when ball is airborne. Thornton broke his thumb as a freshman in 1999 and got a medical redshirt. In 2000, he began his career as a receiver and had 47 receptions and three touchdowns. He moved to defensive back during practices for the Oahu Bowl and has started since. As a senior, he started 13 games and finished with 48 tackles, two interceptions and seven passes broken up. Thornton has adequate size and speed. He is at his best in zone coverage and has good agility and burst coming forward. However, Thornton lacks great man-cover skills and often loses confidence. He lacks great speed and playmaking skills, and he struggles to turn and run with faster receivers. Thornton is a late-round cornerback prospect who must play in a scheme that calls for zone coverage. He could develop into a No. 3 cornerback but does not have upside.