Cason joined receiver Tiquan Underwood in signing free agent deals Friday.
Cason has a career-low 12 tackles last season with Arizona, barely seeing any action. He spent his first five years with the Chargers, with the first three under Ron Rivera, who was San Diego's defensive coordinator then.
In his career, Cason has 14 interceptions and 58 pass deflections.
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Aaron Wilson covers the Ravens for The Baltimore Sun.