Johnson, 27 in June, spent the last four seasons with the Seattle Seahawks as a reserve safety and key special teams player. In 2014, he appeared in 15 games (one start) and recorded 19 tackles with one pass deflection.
Johnson signed with the Redskins to be a starter at strong safety, ESPN.com's John Keim reports.
Johnson appeared to confirm the signing with a tweet Monday afternoon:
The Seahawks gave Johnson a second-round tender as a restricted free agent last offseason. The Redskins new general manager, Scot McCloughan, worked in the Seahawks' front office from 2010 to 2014 as a senior personnel executive.
Over Johnson's 43-game career, he has 27 tackles and one pass deflection.
- Mike Fiammetta