The San Diego Chargers signed cornerback William Middleton to a one-year contract Sunday. The Chargers added some experienced depth to their secondary Sunday, signing former Jaguars cornerback William Middleton, the club said. Middleton spent the last four seasons with Jacksonville. He played in 10 games with three starts last season and finished the year with 18 tackles.Middleton was originally drafted by Atlanta in the fifth round of the 2009 NFL Draft. He played collegiately at Furman.Middleton will wear No. 42 for the Chargers and he will be on the practice field for this afternoon’s practice. He’s played in 49 career games with 12 starts, collecting two interceptions to go along with 100 tackles, six passes defensed and 33 stops on special teams.The 27-year-old Middleton is a native of Marist, Georgia. The Chargers figure to have three new starters in the secondary.