John Butler (born April 3, 1973) is an American football coach who was most recently the defensive backs coach and passing game coordinator for the Buffalo Bills of the National Football League (NFL).
He then progressed to Texas, where he served as a graduate assistant under both John Mackovic and Mack Brown in 1997 and 1998 respectively.
[1] Butler re-united with Roof on Bill O'Brien's staff at Penn State.
After Roof moved back to his alma mater at Georgia Tech, Butler was promoted to defensive coordinator over two more experienced assistants, linebackers coach Ron Vanderlinden and defensive line coach Larry Johnson.
[2][3] In early 2014, Butler left Penn State to join O'Brien's Houston Texans staff as secondary coach.