"He's excited to be coming home, he's a Virginia Tech guy," said his agent, Joel Segal.
Hall should suit up for Washington's next game, on Nov. 16 against Dallas. The Redskins, who have had injury problems in the secondary, have a bye this week.
Hall was released by Oakland earlier this week after playing just eight games with the Raiders. Oakland acquired Hall in the offseason for two draft picks, then signed him to a seven-year, $70 million contract. But he lasted only a half-season with the Raiders, and several players expressed disappointment that was released.
But Hall did struggle in coverage early in the season; he had shown signs of improvement in recent weeks, but was let go anyway following a 24-0 loss to the Falcons that dropped Oakland to 2-6 on the season.
In his eight games in Oakland, Hall was beaten 40 times for 552 yards on 66 passes thrown his way, according to data compiled by STATS. He gave up more yards than any defender this season and was tied for third worst in catches allowed.
In Washington, he joins a 6-3 team that needs help in the defensive backfield. The Redskins also hope cornerback Shawn Springs can return against Dallas after being sidelined with a calf problem.
Hall was one of the first players new general manager Thomas Dimitroff and coach Mike Smith moved out of Atlanta when they took over earlier this year.
