[1] Sierra's film credits include The Flying Nun (1969), Beneath the Planet of the Apes (1970), Papillon (1973), The Towering Inferno (1974), The Prisoner of Zenda (1979) and The Trouble with Spies (1987).

In the plot, he volunteers in helping to chase away neo-Nazi thugs who spray-painted a swastika on the Bunkers' front door.

After that, he spent two years as part of the ensemble cast of Barney Miller, as Detective Sergeant Chano Amengual.

In 1992, Sierra played drug dealer Felix Barbossa in the film Deep Cover, directed by Bill Duke and starring Laurence Fishburne and Jeff Goldblum.

His television credits also include Mod Squad, Kung Fu, Alias Smith and Jones, Mission: Impossible (3 episodes), Hawaii Five-O, Gunsmoke, The Greatest American Hero, Midnight Caller, The Fresh Prince of Bel-Air, The X-Files, Murder, She Wrote, Hart to Hart and Hill Street Blues.

[4] According to his wife, Helene Tabor, he died at age 83 in Laguna Woods, California, on January 4, 2021, after a long battle with stomach and liver cancer.