Thorpe, 26, originally signed on with the Chiefs as an undrafted free agent out of Auburn back in 2012. He spent two years in Kansas City before he signed a future/reserve contract with the Raiders at the end of 2014.
Thorpe returned to Oakland on a one-year exclusive rights deal last year, but elected to cut him loose a few weeks ago. The Colts later claimed him off waivers only to cut him a few days later.
In 2015, Thorpe appeared in 14 games for the Raiders and recorded 40 tackles, one interception, and six pass defenses.