For the 30-year-old Florida product, Oakland will be his third stop in as many seasons.
Sheppard posted 18 tackles in 13 games a season ago with the Minnesota Vikings. In 2009, the diminutive but speedy corner racked up 31 tackles and one interception over 11 games with the Jets.
The former first-round draft pick of the Philadelphia Eagles in 2002, Sheppard has totaled 302 tackles, 19 interceptions -- including three for TDs -- and two sacks in 117 games over nine NFL seasons. He played for the Birds from 2002-08.