The Jefferson County Coroner's Office said Gray, 25, was found shortly before 10 p.m. Monday near Birmingham. He is a native of Pinson, Alabama.
According to Al.com, sheriff's deputies and Center Point Fire and Rescue were dispatched to the house after a friend found Gray wounded and unresponsive.
After transferring from junior college, Gray started one season for the Wolfpack before entering the NFL draft after his sophomore season, when he had 2.5 sacks. He played in four preseason games for the Packers in 2014 and was released in 2015.
The Associated Press contributed to this report.