Question: In what year was the author who wrote the true crime book "Helter Skelter" with Curt Gentry born?

Context articles: John Gilmore (writer)
Helter Skelter (book)
Deaths on Pleasant Street
Curt Gentry
In Broad Daylight
Murder in Mississippi (book)
Helter Skelter (1976 film)
Vincent Bugliosi
John Roecker
Murder on the High Seas (book)

John "Jonathan" Gilmore (July 5, 1935 - October 13, 2016) was an American author and gonzo journalist known for iconoclastic Hollywood memoirs, true crime literature and hard-boiled fiction.
 A motion picture, television and stage actor in Los Angeles and New York in the 1950s, his friends including James Dean and Marilyn Monroe, Gilmore has also written about his encounter with Elizabeth Short a.k.a. "The Black Dahlia" during his youth.
 Gilmore emerged as a writer from the Beat Generation in the '60s, influenced by Jack Kerouac and befriended by author William S. Burroughs.
 The publication of his true crime book "Severed: The True Story of the Black Dahlia," ushered in a cult following for the author.
 His manuscripts and original writings are housed in the special collections department of the Research Library of the University of California at Los Angeles.
Helter Skelter (1974) is a true crime book by Vincent Bugliosi and Curt Gentry.
 Bugliosi had served as the prosecutor in the 1970 trial of Charles Manson.
 The book presents his firsthand account of the cases of Manson, Susan Atkins, Patricia Krenwinkel, and other members of the self-described Manson Family.
 It is the best-selling true crime book in history.
Deaths on Pleasant Street: The Ghastly Enigma of Colonel Swope and Doctor Hyde (ISBN  ) is a non-fiction book describing the suspicious deaths of three members of the prominent Swope family of Independence Mo.
 The deaths took place in the fall and winter of 1909, in the family's 26-room gothic mansion.
 Author Giles Fowler presents evidence that at least two of the deaths were murders, committed by Dr. Bennett Clark Hyde, who was married to a Swope heiress.
 The first Hyde trial, for the murder of philanthropist Thomas Hunton Swope, was covered by virtually every major newspaper in the United States.
 Fowler's book, published by the Truman State University Press, was winner of the Jackson County, MO.
 Historical Society's Historic Book of the Year award, in 2009, and a 2009 ForeWord award as True Crime Book of the Year.
Curtis Marsena "Curt" Gentry (June 13, 1931 – July 10, 2014) was an American writer, born in Lamar, Colorado.
 He is best known for co-authoring, with Vincent Bugliosi, the 1974 book "Helter Skelter", which detailed the Charles Manson murders.
 Gentry lived in San Francisco, California.
In Broad Daylight is a true crime book by award-winning writer Harry N. MacLean, detailing the killing of town bully Ken Rex McElroy in 1981 in Skidmore, Missouri.
 The book won an Edgar Award for best true crime writing in 1989, was a "New York Times" bestseller for 12 weeks (charting at number 2) and was adapted into a television movie of the same name.
 The book was reissued in 2007 by St. Martin's Press with a new epilogue.
Murder in Mississippi: The True Story of How I Met a White Supremacist, Befriended His Black Killer and Wrote this Book is a 2013 true crime book written by Australian author and documentary-maker John Safran.
 It was published as God'll Cut You Down in the US.
 The book won the 2014 Ned Kelly Award for True Crime.
Helter Skelter is a 1976 television film based on the 1974 book by prosecutor Vincent Bugliosi and Curt Gentry.
 In the United States, it aired over two nights.
 In some countries it was shown in theaters with additional footage (nudity, language and more violence).
Vincent T. Bugliosi, Jr. ( ; August 18, 1934 – June 6, 2015) was an American attorney and "New York Times" bestselling author.
 During his eight years in the Los Angeles County district attorney's office, he successfully prosecuted 105 out of 106 felony jury trials, which included 21 murder convictions without a single loss.
 He was best known for prosecuting Charles Manson and other defendants accused of the seven Tate–LaBianca murders of August 9–10, 1969.
 Although Manson did not physically participate in the murders at Sharon Tate's home, Bugliosi used circumstantial evidence to show that he had orchestrated the killings.
John Roecker is an independent filmmaker who is associated with the punk subculture.
 He currently resides in Los Angeles, California.
 Roecker is probably best known for "Live Freaky!
 Die Freaky!
", a stop motion animated comedy based on the true crime book "Helter Skelter".
Murder on the High Seas – "The True Story of the Joe Cool's Tragic Final Voyage" is a true crime book written by Carol Soret Cope, bestselling author of "In the Fast Lane: A True Story of Murder in Miami" and "Stranger Danger: How to Keep Your Child Safe".
 The book explores the investigation into the mysterious murders aboard the Joe Cool.