McCray, who signed a one-year deal Thursday, spent his first four years in Dallas as an undrafted free agent in 2010. He played in Chicago last season.
The 27-year-old McCray is also a backup safety but was second in tackles for an injury-plagued Dallas defense in 2012. He made all 10 of his career starts that season.
McCray is sixth in Cowboys history with 73 special teams tackles.
The Cowboys also signed tight end Geoff Swaim, a seventh-round pick out of Texas, and rookie free agent linebacker Donnie Baggs of Texas A&M.
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