Question: Helter Skelter presented the firsthand account of the case of the murderer who was a part of whose "family"?

Context paragraphs:
Helter skelter (ride): A helter skelter is an amusement ride with a slide built in a spiral around a high tower.  Users climb up inside the tower and slide down the outside, usually on a mat or hessian (burlap) sack.  Typically the ride will be of wooden construction and, in the case of fairground versions, designed to be disassembled to facilitate transportation between sites.  The term is primarily (but not exclusively) found in the United Kingdom.  In the United States, the ride is uncommon and may be called by other names, such as a "Skyslide".

My Life in Orange: My Life in Orange: Growing Up with the Guru is an account of a child growing up in the Rajneesh movement led by Bhagwan Shree Rajneesh.  The book is a firsthand account, written by Tim Guest at the age of 27, years after his experiences.  The book was published in 2004 by Granta Books.  The book's title is a reference to the term "the orange people", which was used to refer to members of the Rajneesh movement due to the color they dyed their clothes.

Susan Atkins: Susan Denise Atkins (May 7, 1948 September 24, 2009) was a convicted American murderer who was a member of Charles Manson's "Family".  Manson and his followers committed a series of nine murders at four locations in California, over a period of five weeks in the summer of 1969.  Known within the Manson family as Sadie Mae Glutz or Sexy Sadie, Atkins was convicted for her participation in eight of these killings, including the most notorious, the "Tate/LaBianca" murders.  She was sentenced to death, which was subsequently commuted to life in prison.  Atkins was incarcerated from October 1, 1969, until her death – a period exactly one week short of 40 years.  At the time of her death, Atkins was California's longest-serving female inmate.

Helter Skelter (album): Helter Skelter is the second studio album by The D.O.C.; released on January 23, 1996.  This album was an attempt at making a comeback following the car crash which severely damaged his vocal cords.  The album was widely ignored, and has even been discredited by D.O.C himself.  The name of the album is a reference to Charles Manson's idea of The Beatles' "Helter Skelter" prophesying the end of the world.

Lourenço da Silva de Mendouça: Lourenço da Silva de Mendouça (1620–1698), probably born in Brazil, went to Lisbon in 1681, then Madrid in 1682 where he became procurator-general of the Confraternity of Our Lady, Star of the Negroes, a charitable lay society in Brazil and Portuguese Africa.  Lourenço, claiming to be descended from kings of Kongo and Angola, travelled to Rome in 1684 to protest to the Pope against slavery.  His petitions, which presented a firsthand account of the cruelties inflicted by slavery, supported by Capuchin missionaries, convinced the Sacred Congregation for the Propagation of the Faith and led directly to the March 20th, 1686 condemnation by Pope Innocent XI.

Tex Watson: Charles Denton "Tex" Watson (born December 2, 1945) is an American murderer who was a central member of the "Manson family" led by Charles Manson.  On August 9, 1969, Watson and other Manson followers murdered pregnant actress Sharon Tate and four other people at a house in Benedict Canyon, Los Angeles.  The next night, Watson traveled to Los Feliz, Los Angeles, and participated in the murders of Leno and Rosemary LaBianca, as part of Manson's "Helter Skelter" vision.  Watson was found guilty of murder and imprisoned in 1971.

Helter Skelter: L.A. Art in the 1990s: Helter Skelter: L.A. Art in the 1990s, named after The Beatles' song that motivated Charles Manson, was a contemporary art exhibition held from January 26, to April 26, 1992 at the L.A. Museum of Contemporary Art.  Organized by Paul Schimmel, "Helter Skelter" displayed the work of 16 artists.  Featuring works of sex, violence, and warped Americana, the exhibition aimed to destroy stereotypes of L.A. art and challenge the New York school.  At the time "Helter Skelter" was hailed as the prime example of modern contemporary art and is still held as one of the most important and influential contemporary art exhibits in recent years.

The Guns of Normandy: The Guns of Normandy: A Soldier's Eye View, France 1944 is a non-fiction book, written by Canadian writer George G. Blackburn, first published in October 1995 by McClelland & Stewart.  In the book, the author renders a firsthand account of the Normandy invasion from within the Canadian Forces.  The narrative account was called "gripping", given in "the most graphic and authentic detail".  The panel of judges who awarded the "Edna Staebler Award for Creative Non-Fiction" called "The Guns of Normandy" "an outstanding example" of the genre.

Helter Skelter (book): 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.

Helter Skelter (song): "Helter Skelter" is a song by the English rock band the Beatles that was released in 1968 on their self-titled double album, often known as "the White Album".  It was written by Paul McCartney and credited to Lennon–McCartney.  The song was a product of McCartney's attempt to create a sound as loud and dirty as possible.  The Beatles' recording has been noted for its "proto-metal roar" and is considered by music historians to be a key influence in the early development of heavy metal. " Rolling Stone" magazine ranked "Helter Skelter" 52nd on its list of the "100 Greatest Beatles songs".

Supporting paragraphs: Helter Skelter (book) Susan Atkins
Answer: Charles Manson