Änderungen
rep.
Er spielte [[Captain]] [[Styles]] in {{Film|3}}.
Neben ''[[Star Trek]]'' hatte Sikking Rollen im Filmen wie ''Die Unersättlichen'' (1964, u.a. mit [[Paul Baxley]], [[Peter Duryea]], [[Ed McCready]] und [[William Meader]]), ''Derek Flint – hart wie Feuerstein'' (1967, u.a. mit [[Steve Ihnat]] und [[Yvonne Craig]]), ''Point Blank - Keiner darf Überleben'' (1967, u.a. mit [[Michael Strong]], [[Sharon Acker]], [[Sid Haig]], [[Michael Bell]], [[Jerry Catron]], [[Chuck Hicks]], [[Joseph Mell]] und [[Felix Silla]]), ''Der Mann mit dem Katzenkäfig'' (1969, u.a. mit [[Gene Lyons]]), ''Flucht vom Planet der Affen'' (1971, u.a. mit [[Ricardo Montalban]], [[William Windom]], [[Jason Evers]], [[Karl Bruck]], [[Walker Edmiston]] und [[Janos Prohaska]]), ''Man on a String'' (TV 1972, u.a. mit [[William Schallert]], [[Joel Grey]], [[Barry Russo]], [[Lincoln Demyan]], [[Carolyn Nelson]], [[Garry Walberg]] und [[Byron Morrow]]), ''Scorpio, der Killer'' (1973, u.a. mit [[John Colicos]], [[Joanne Linville]], [[William Smithers]], [[Celeste Yarnall]] und [[Morgan Farley]]), ''Im letzten Moment'' (TV 1973, u.a. mit [[Leonard Nimoy]], [[Victor Tayback]], [[Kenneth Tobey]], [[Paul Kent]], [[Paul Sorensen]] und [[Tom Troupe]]), ''The F.B.I. Story: The FBI Versus Alvin Karpis, Public Enemy Number One'' (TV 1974, u.a. mit [[Robert Foxworth]], [[Gary Lockwood]], [[Harris Yulin]], [[Whit Bissell]], [[Lenore Kasdorf]], [[Arch Whiting]], [[Bill Zuckert]] und [[Dallas Mitchell]]), ''First Steps'' (TV 1985, u.a. mit [[Kim Darby]], [[Alan Ruck]], [[Dawn Arnemann]], [[Molly Hagan]], [[William O. Campbell]], [[Bill BlairPeggy Roeder]] und [[Peggy RoederBill Blair]]) und ''Los Angeles Police: Mord auf dem Freeway'' (TV 1987, u.a. mit [[Robert Knepper]], [[Marc Alaimo]], [[Javier Grajeda]], [[Kamala Lopez-Dawson]] und [[John Bellah]]).
In der TV-Serie ''Polizeirevier Hill Street'' (1981-1987, u.a. mit [[Barbara Bosson]], [[Megan Gallagher]], [[Barbara Babcock]], [[Marco Rodriguez]], [[David Selburg]], [[Louis Giambalvo]], [[Lawrence Tierney]], Marc Alaimo, [[Daniel Zacapa]], [[Morgan Woodward]], [[Michael Durrell]], [[Gregory Sierra]], [[Biff Yeager]], [[Clayton Rohner]], [[George Coe]], [[Robin Gammell]], [[Alfre Woodard]], [[Eric Pierpoint]], [[Phil Rubenstein]], [[James Avery]], [[Robert Costanzo]], [[Hamilton Camp]], [[John Hancock]], [[Stanley Kamel]], [[Tim Russ]], [[Granville Van Dusen]], [[Stephen McHattie]], [[Gary Frank]], [[Jonathan Banks]], [[Gail Strickland]], [[Tracey Walter]], [[Robert Sampson]], [[Mickey Morton]], [[Anne Haney]], [[Milt Tarver]], [[Carlos LaCamara]], [[Kenneth Tigar]], [[Tony Plana]], [[Karole Selmon]], [[J. Patrick McNamara]], [[Ted Gehring]], [[Jimmie F. Skaggs]], [[Jefrey Alan Chandler]], [[Stephen Macht]], [[Martha Hackett]], [[Brian McNamara]], [[Lawrence Pressman]], [[Margot Rose]], [[Clarence Williams III]], [[Dwight Schultz]], [[David Spielberg]], [[Jonathan Frakes]], [[George Murdock]], [[James Saito]], [[Julianna McCarthy]], [[Raye Birk]], [[Robert DoQui]], [[Peter Brocco]], [[Victor Brandt]], [[Sierra Pecheur]], [[Janet MacLachlan]], [[Bruce French]], [[Brent Spiner]], [[Eric Server]], [[Penny Johnson]], [[Sam Anderson]], [[Davis Roberts]], [[Tina Lifford]], [[Richard McGonagle]], [[Armin Shimerman]], [[Michael Ensign]], [[Robert O'Reilly]], [[Paul Eiding]], [[Faith Minton]], [[John Chandler]], [[Evelyn Guerrero]], [[Gregory Itzin]], [[Merritt Butrick]], [[Phillip Pine]], [[Charles Cooper]], [[Mario Roccuzzo]], [[Carl Byrd]], [[Vince Howard]], [[Georgia Schmidt]], [[Louie Elias]], [[Saul Rubinek]], [[James Cromwell]], [[Shelly Desai]], [[Gene Dynarski]], [[Matthew Faison]], [[John D. Gowans]], Sid Haig, [[Larry Hankin]], [[Alex Henteloff]], [[John Hostetter]], [[Ada Maris]], [[Joseph Ruskin]], [[Marcelo Tubert]], [[Gregory Wagrowski]], [[Ed Bakey]], [[Earl Boen]], [[Rick Fitts]], [[Brian George]], [[Michael Keenan]], [[Jack Kehler]], [[Nancy Vawter]], [[Steve Vinovich]], [[Jason Wingreen]], [[John Fleck]], [[Richard Herd]], [[Judith Jones]], [[Tom McCleister]] und [[Eric Menyuk]]) spielte er als eine der Hauptfiguren die Rolle des Lieutenant Howard Hunter, in ''Doogie Howser'' (1989-1993, u.a. mit Lawrence Pressman, [[Rif Hutton]], David Selburg, [[Paul Lambert]], Jefrey Alan Chandler, [[Tim O'Connor]], [[Julie Cobb]], [[Nana Visitor]], [[Ron Canada]], [[Bruce Gray]], [[Thelma Lee]], [[Mark L. Taylor]], Paul Eiding, [[Leslie Morris]], Paul Kent, [[Jeff McCarthy]], Granville Van Dusen, [[Roy Brocksmith]], [[Ursaline Bryant]], [[Larry Cedar]], [[Bob Minor]], [[Christopher Pettiet]], [[René Auberjonois]], Anne Haney, [[Gwen Van Dam]], John D. Gowans, [[John Christian Graas]], [[Deborah Lacey]], [[Stephen Lee]], [[Andrew Hill Newman]], [[Angela Paton]], [[Nehemiah Persoff]], [[Joel Polis]], [[Freda Foh Shen]], [[Marcelo Tubert]], [[Eve Brenner]], Robert Costanzo, [[Patrick Cronin]], [[Annie O'Donnell]], [[Tricia O'Neil]], [[Jeff Yagher]] und [[Ed O'Ross]]) die des Doktor David Howser und in ''Brooklyn South'' (1997-1998, u.a. mit [[Titus Welliver]], [[Jana Marie Hupp]], [[Dennis Creaghan]], [[John Cothran Jr.]], [[Joel Brooks]], [[Theodore Bikel]], [[Steven Flynn]], [[Joseph Ruskin]], [[John Prosky]], Richard McGonagle, [[Jack Shearer]], [[David Selburg]], Stephen Lee, [[Mark Rolston]], [[Caitlin Brown]], [[Vinny Argiro]], [[Joseph Fuqua]], [[Jack Blessing]], [[Bill Bolender]], [[Brigid Brannagh]], [[Jimmy Ortega]], [[Scott Jaeck]], [[Jennifer Hetrick]], [[Mike Genovese]], [[Don Stark]], [[L.L. Ginter]], Javier Grajeda, [[Miguel Perez]], Brian George, [[Viola Stimpson]], [[Georgann Johnson]], [[Louis Giambalvo]], [[Michael Bofshever]], [[Tony Plana]] und [[Leland Orser]]) die des Captain Stan Jones.