Trainor as Diane Evans: Max and Isabel's adoptive mother Diane Farr as Amy DeLuca: Maria's single mother John Doe as Jeff Parker: Liz's father and owner of the Crashdown Cafe Jo Anderson as Nancy Parker: Liz's mother Nicholas Stratton as Young Michael (season 1): Appears in several flashback sequences Julie Benz as Kathleen Topolsky (season 1): FBI agent posing as a high school guidance counselor Jim Ortlieb as Nasedo (seasons 1–2): Alien sent from Antar to watch over the Royal Four. He has the ability to shapeshift. Michael Horse as Deputy Owen Blackwood: Sheriff Jim Valenti's assistant Steve Hytner as Milton Ross (season 1): Owner of the UFO center Richard Schiff as Agent John Stevens (season 1): FBI agent from the special unit assigned to discover if aliens exist David Conrad as Deputy David "Dave" Fisher/FBI Agent Daniel Pierce (seasons 1–2): Head of the FBI special unit assigned to discover if aliens exist Devon Gummersall as Sean DeLuca (season 2): Maria's delinquent cousin who has feelings for Liz Desmond Askew as Brody Davis/Larek (season 2): New owner of the UFO center who has a young daughter and passion for researching aliens Gretchen Egolf as Congresswoman Vanessa Whitaker (season 2): Congresswoman for whom Liz is an assistant before her identity as a skin is discovered Sara Downing as Courtney Banks (season 2): "Skin" who works at the Cafe and thinks Michael should be the leader of the Royal Four Miko Hughes as Nicholas Crawford (season 2): Powerful "Skin" who has the appearance of a teenage boy Guest stars Daniel Hansen as Young Max (season 1) Sebastian Siegel as Brad Carroll Baker as Grandma Claudia (season 1) John Cullum as James Valenti Sr. (season 1) Jonathan Frakes as Himself (seasons 1 and 3) Genie Francis as Queen Mother of Antar (season 1) Erica Gimpel as Agent Susan Duff Ned Romero as River Dog, old native American man (season 1) Howie Dorough as Alien (season 1) Nelly Furtado as Herself (season 2) Jason Dohring as Jerry (season 2) Spence Decker as Kivar (season 3) Morgan Fairchild as Meris Wheeler (season 3) Joe Pantoliano as Kal Langley (season 3) John Billingsley as Himself (season 3) Episodes Production Roswell High was originally developed by 20th Century Fox Television and Regency Television for the Fox Network, though it eventually landed on The WB (retitled simply to Roswell) thanks to the latter network's offer to extend a