Townsend appeared in 191 games with 80 starts for the Steelers (1998-2009) and Colts (2010), registering 428 tackles, 21 interceptions, 15.5 sacks, three touchdowns, five forced fumbles and four fumble recoveries. He was a key member of Steelers teams that beat the Seahawks in Super Bowl XL and the Cardinals in Super Bowl XLIII. Townsend helped secure Pittsburgh's win over Seattle with a late sack of Matt Hasselbeck.

Townsend has spent five seasons as an NFL assistant defensive backs coach with the Cardinals (2011-12), Titans (2016-17) and Giants (2018). A player he worked with was voted to the Pro Bowl with all three teams.

In Arizona, he helped cornerback Patrick Peterson earn back-to-back Pro Bowl invitations in 2011-12 as well as AP All-Pro honors as a rookie in 2011.

With the Titans in 2017, Townsend coached safety Kevin Byard, who was voted to the Pro Bowl after tying for the NFL lead with eight interceptions.

In 2018, Townsend coached safety Landon Collins, who also earned Pro Bowl honors. Collins was second among NFL defensive backs with 96 tackles before being placed on injured reserve with a shoulder injury he sustained Dec. 3 against the Bears.

From 2013-15, Townsend was the cornerbacks coach at Mississippi State. In 2014, he helped the Bulldogs defense lead the nation in passes defensed (89).

The Bears on Friday also hired Ronell Williams as their defensive quality control coach.