The Raiders signed free-agent cornerback Mike Jenkins and re-signed defensive end Andre Carter on Tuesday. Both were one-year contracts, with terms not disclosed yet. Jenkins, 28, is the second experienced starter Oakland has added to a bare secondary the last two weeks. Last week, the Raiders signed former Saints and Broncos cornerback Tracy Porter, who played only six games last season because of problems with seizures and a concussion. A league source confirmed that Jenkins passed up a potential multi-year contract. He wants to prove himself this season and hit the free-agent market again next year. Jenkins, who went to the Pro Bowl in 2009, spent the past five seasons with the Dallas Cowboys, starting 48 games in his career but only two last season. He lost his starting job last season when the Cowboys signed Brandon Carr and drafted Morris Claiborne. “Jenkins is very capable, I think a good cornerback,” Cowboys owner Jerry Jones said in March. “We happen to be pretty committed relative to the rest of our roster. We have to be pretty committed at cornerback.