Career
Mackey played at Gavilan College, before transferring to the University of Akron. He was signed as an undrafted free agent by the Dallas Cowboys after a tryout on August 12, 2001. He was released before the season started and signed to the practice squad.
He was promoted to the active roster on November 16 and played in only one game against the Philadelphia Eagles, before being placed on the injured reserve list with a fractured tibia on November 21.
After being released on August 28, 2002, he was signed to the team"s practice squad. On September 13, he was moved to the active roster and would proceed to lead the team in special teams tackles with 18.
He was waived on August 17, 2003.