With the Bears pick up of Rod Hood they are helping the depth of the Bears secondary, especially with Charles Tillman and Zackary Bowman still working with injuries, but they might not be done.
According to a small bit at the end of this article, the Bears have looked at at least one other:
A league source also said the Bears have inquired about Chris McAlister, the former Pro Bowl performer for the Baltimore Ravens who has worked his way back from knee surgery.
It is unclear when during the offseason they inquried about him. This may now be dead news.
At one time McAllister was one of the premiere cornerbacks in the league. At this point I don't know how much he has left.