Laurence George Luckinbill (born November 21, 1934) is an American actor. Luckinbill was born in Fort Smith, Arkansas, the son of Agnes (née Nulph) and Laurence Benedict Luckinbill. He graduated from the University of Arkansas in 1956 and The Catholic University of America in 1958. He starred in the 1976 Broadway play Poor Murderer. He portrayed Spock's half-brother Sybok in Star Trek V: The Final Frontier (1989). He also appeared in The Boys in the Band, reprising the part of Hank, which he originated on stage. Other film appearances include Such Good Friends, Cocktail, and The Promise, and he has been seen in numerous television shows, including Law & Order, Barnaby Jones and Murder, She Wrote. His acting career has also included writing and directing. He has written and performed in several one-man shows including, "Hemingway", "Teddy", "An Evening with Clarence Darrow", as well as, "Lyndon", which he didn't write, but has performed numerous times, including a schedule at the LBJ Museum in Austin, Texas, where Lady Bird Johnson was one of those in attendance. He narrated the documentary Moonwalk One which has recently been restored and re-released.