Gilyard was known for his roles as second private investigator and right-hand man Conrad McMasters to Ben Matlock (played by Andy Griffith) on the legal drama series Matlock from 1989 to 1993; Pastor Bruce Barnes in the first two Left Behind movies; Cordell Walker's (played by Chuck Norris) Texas Ranger partner, James "Jimmy" Trivette, in the 1990s crime drama Walker, Texas Ranger; Theo, the terrorist computer expert in Die Hard; and Lieutenant (junior grade) Evan "Sundown" Gough in Top Gun.