Shepherd played his college ball at Tyler Community College in Tyler, Texas where he transferred to Oklahoma State University during his junior year in 1998.
In 2000 Shepherd was drafted by the St. Louis Rams in the second round of the NFL Draft. As a rookie he played in 15 games. During the 2001 season Jacoby was hampered by a hamstring injury.
In 2002 the Houston Texans traded a conditional draft pick in the 2003 NFL Draft to the Rams in return for Shepherd. Unfortunately, he was waived by the Texans later that year. For the next several seasons Shepherd landed with the Jets, Lions, Raiders & Packers.