Question: Which American actor, screenwriter, poet and singer died in 1999 and acted in Amok Time?

full_context: Document 1: Star Trek III: The Search for Spock: Star Trek III: The Search for Spock is a 1984 American science fiction film directed by Leonard Nimoy and based on the created by Gene Roddenberry. It is the third film in the "Star Trek" film series, and is the second part of a three-film story arc that begins with "" (1982) and concludes with "" (1986). After the death of Spock (Nimoy), the crew of the USS "Enterprise" returns to Earth. When James T. Kirk (William Shatner) learns that Spock's spirit, or katra, is held in the mind of Dr. Leonard "Bones" McCoy (DeForest Kelley), Kirk and company steal the "Enterprise" to return Spock's body to his home planet. The crew must also contend with hostile Klingons led by Kruge (Christopher Lloyd) who are bent on stealing the secrets of a powerful terraforming device.
Document 2: The Monsters Are Due on Maple Street: "The Monsters Are Due on Maple Street" is episode 22 in the first season of the American television anthology series "The Twilight Zone". The episode was written by Rod Serling, the creator-narrator of the series. It originally aired on March 4, 1960 on CBS. In 2009, "TIME" named it one of the ten best "Twilight Zone" episodes.
Document 3: The City on the Edge of Forever: "The City on the Edge of Forever" is the 28th episode of the American science fiction television series "", and the penultimate episode of the . It was first broadcast in the United States on NBC on April 6, 1967. In the episode, after Doctor Leonard McCoy (DeForest Kelley) travels back in time and changes history, Kirk (William Shatner) and Spock (Leonard Nimoy) follow him to correct the timeline. In doing so, Kirk falls in love with Edith Keeler (Joan Collins), but realizes that in order to save his future, he must allow her to die.
Document 4: The Impossible Astronaut: "The Impossible Astronaut" is the first episode of the sixth series of the British science fiction television series "Doctor Who". Written by show runner Steven Moffat, and directed by Toby Haynes, the episode was first broadcast on 23 April 2011 in the United Kingdom, as well as the United States and Canada. It also aired in Australia on 30 April 2011. The episode features alien time traveller the Doctor (Matt Smith) and his companions Amy Pond (Karen Gillan) and Rory Williams (Arthur Darvill), and is the first of a two-part story, which concluded with "Day of the Moon".
Document 5: Leonard Nimoy: Leonard Simon Nimoy ( ; March 26, 1931 – February 27, 2015) was an American actor, film director, photographer, author, singer and songwriter. He was best known for his role as Spock of the "Star Trek" franchise, a character he portrayed in television and film from shot in late 1964 to his final film performance in 2013.
Document 6: The Cage (Star Trek: The Original Series): "The Cage" is the first pilot episode of the American television series "." It was completed in early 1965 (with a copyright date of 1964), but not broadcast on television in its complete form until late 1988. The episode was written by Gene Roddenberry and directed by Robert Butler. It was rejected by NBC in February 1965, and the network ordered another pilot episode, which became "Where No Man Has Gone Before."
Document 7: Karl Urban: Karl-Heinz Urban (born 7 June 1972) is a New Zealand actor. He is known for playing Julius Caesar and Cupid in "" and "", Éomer in the and installments of Peter Jackson's "The Lord of the Rings" trilogy, Vaako in second and third installments of the "Riddick" film series, Dr. Leonard "Bones" McCoy in "Star Trek", "Star Trek Into Darkness" and "Star Trek Beyond", and Judge Dredd in "Dredd". He won acclaim for his performances in New Zealand films "The Price of Milk" and "Out of the Blue". He also played the main character John Kennex in the short-lived television series "Almost Human". He will play Skurge in the Marvel Studios film "" set for a November 3, 2017 release.
Document 8: Kelsey Grammer: Allen Kelsey Grammer (born February 21, 1955) is an American actor, voice actor, comedian, producer, director, writer, singer, and activist.
Document 9: DeForest Kelley: Jackson DeForest Kelley (January 20, 1920 – June 11, 1999) was an American actor, screenwriter, poet and singer known for his roles in Westerns and as Dr. Leonard "Bones" McCoy of the USS "Enterprise" in the television and film series "Star Trek".
Document 10: Amok Time: "Amok Time" is the premiere episode of the American science fiction television series, "". It is episode #30, production #34, first broadcast on September 15, 1967, in the series' new time slot of 8:30 pm on Friday night, and repeated April 26, 1968. It was the first episode to air (though not the first filmed) featuring regular cast member Walter Koenig, as the ship's navigator, Ensign Pavel Chekov, and also the first one to list DeForest Kelley as Dr. McCoy in the opening credits. It was written by science fiction author Theodore Sturgeon, scored by Gerald Fried, and directed by Joseph Pevney.
Document 11: The Infinite Vulcan: "The Infinite Vulcan" is the seventh episode of the of the American animated science fiction television series "". It first aired on NBC on October 20, 1973, and was written by "" cast member Walter Koenig. It was the actor's only involvement in the series, as he had not been hired to voice Pavel Chekov in the animated version due to financial issues with production. With "The Infinite Vulcan", Koenig became the first member of the "Star Trek" cast to write an episode for the franchise. As with many episodes of the show, the episode was directed by Hal Sutherland.
Document 12: List of Star Trek: The Original Series episodes: Created by Gene Roddenberry, the science fiction television series "" (which eventually acquired the retronym "Star Trek: The Original Series") starred William Shatner as Captain Kirk, Leonard Nimoy as Mr. Spock, and DeForest Kelley as Dr. Leonard "Bones" McCoy aboard the fictional Federation starship USS "Enterprise". The series originally aired from September 1966 through June 1969 on NBC.
Document 13: These Are The Voyages: TOS, Season Two: These Are The Voyages: TOS, Season Two is a non-fiction reference book by Marc Cushman with Susan Osborn and with foreword by Walter Koenig (who played Pavel Chekov) about the second season of "". The information revealed inside primarily comes from production documents that were donated by Gene Roddenberry and Robert H. Justman to the UCLA Film and Television Archive.
Document 14: Alan Alda: Alan Alda ( ; born Alphonso Joseph D'Abruzzo; January 28, 1936) is an American actor, director, screenwriter, and author. A seven-time Emmy Award and Golden Globe Award winner, he is widely known for his roles as Captain Hawkeye Pierce in the TV series "M*A*S*H" (1972–1983), hosting of "Scientific American Frontiers", and as Arnold Vinick in "The West Wing" (2004–2006). He has also appeared in many feature films, most notably in "Crimes and Misdemeanors" (1989), as pretentious television producer Lester, and "The Aviator" (2004) as U.S. Senator Owen Brewster, the latter of which saw Alda nominated for the Academy Award for Best Supporting Actor.
Document 15: The City on the Edge of Forever: "The City on the Edge of Forever" is the 28th episode of the American science fiction television series "", and the penultimate episode of the . It was first broadcast in the United States on NBC on April 6, 1967. In the episode, after Doctor Leonard McCoy (DeForest Kelley) travels back in time and changes history, Kirk (William Shatner) and Spock (Leonard Nimoy) follow him to correct the timeline. In doing so, Kirk falls in love with Edith Keeler (Joan Collins), but realizes that in order to save his future, he must allow her to die.
ground_truth: DeForest Kelley