Mitchell attended Sam Houston High School in Arlington, Texas, where he was a first-team 5A All-State selection as a wide receiver.

In his two years as a cornerback, he registered 57 tackles, five interceptions, 10 pass breakups and a forced fumble.

Mitchell was able to participate in training camp in 2006, but was waived prior to the regular season on September 2.

On December 27, Mitchell was promoted to the active roster when cornerbacks Andre' Goodman and Eddie Jackson were placed on Injured Reserve.

In nine starts for the Galaxy, Mitchell recorded 31 tackles, two interceptions (including one returned 81 yards for a touchdown) and nine passes defensed.

Mitchell remained unsigned for the majority of the 2007 season, until he was signed to the practice squad of the Detroit Lions on December 19.