Question: Who is the half-brother of the man whose mother was also known as M. Bible?

full_context: Document 1: Annie Laurie Gaylor: Annie Laurie Gaylor (born November 2, 1955) is a co-founder of – and, with her husband Dan Barker, a current co-president of – the Freedom From Religion Foundation. She was also the editor of the organization's newspaper, "Freethought Today" (published ten times per year) until 2015. Gaylor is the author of several books, including "Woe to the Women: The Bible Tells Me So", "Betrayal of Trust: Clergy Abuse of Children" and, as editor, "Women Without Superstition: No GodsNo Masters". She graduated from the University of Wisconsin–Madison's School of Journalism in 1980.
Document 2: Megan Phelps-Roper: Megan Phelps-Roper (born January 31, 1986) is a social media activist, lobbying to overcome divisions and hatred between religious and political divides. Formerly a prominent member of the Westboro Baptist Church (WBC), she left the church with her sister Grace in November 2012. Her mother is Shirley Phelps-Roper, whose father was the church's founder Fred Phelps.
Document 3: Sonia Johnson: Sonia Johnson (born Sonia Ann Harris; February 27, 1936) is an American feminist activist and writer. She was an outspoken supporter of the Equal Rights Amendment (ERA) and in the late 1970s was publicly critical of the position of The Church of Jesus Christ of Latter-day Saints (LDS Church), of which she was a member, against the proposed amendment. She eventually was excommunicated from the church for her activities. She went on to publish several radical feminist books and become a popular feminist speaker.
Document 4: Jon Garth Murray: Jon Garth Murray (November 16, 1954 – September 29, 1995) was the second son of late controversial activist Madalyn Murray O'Hair, the first president and founder of American Atheists, Inc., in 1963. He was also the half-brother of the reverend William "Bill" Murray.
Document 5: Murray Dry: Murray Dry is an American political scientist specializing in American constitutional law, American political thought, political philosophy, freedom of speech, freedom of religion, federalism, separation of powers, and the American founding. He is perhaps most noted for having helped to compile "The Complete Anti-Federalist" with his former teacher Herbert Storing. He is currently the Charles A. Dana Professor of Political Science at Middlebury College, having earned his BA, MA, and Ph.D at the University of Chicago, where he studied under Storing and Leo Strauss, among others. For the 2009-2010 academic year, he was a Visiting Professor at Yeshiva University. His current area of research is in the constitutionality of same-sex marriage, and he is working on a book on that subject.
Document 6: David Silverman (activist): David "Dave" Silverman (born August 13, 1966) is the current president of the American Atheists, a non-profit organization that supports the rights of atheists and the removal of expressions of religion in public when possibly interpretable as governmental endorsement, in accordance with the First Amendment of the United States Constitution. His annual anti-Christmas billboard which calls Christmas "a myth" has often sparked controversy.
Document 7: William J. Murray: William J. "Bill" Murray III (born May 25, 1946) is an American author, Baptist minister, and social conservative lobbyist who currently serves as the chairman of the Religious Freedom Coalition, a non-profit organization in Washington, D.C., active on issues related to aiding Christians in Islamic and Communist countries. The son of the late atheist Madalyn Murray O'Hair, Murray played a significant part alongside his mother in the ending of mandatory prayer in public schools in 1963.
Document 8: Dan Barker: Daniel Edwin Barker (born June 25, 1949) is an American atheist activist who served as a Christian preacher and musician for 19 years but left Christianity in 1984. He and his wife Annie Laurie Gaylor are the current co-presidents of the Freedom From Religion Foundation. He has written numerous articles for "Freethought Today", an American freethought newspaper. He is the author of several books including "Losing Faith in Faith: From Preacher to Atheist".
Document 9: Norma McCorvey: Norma Leah McCorvey Nelson; (September 22, 1947 – February 18, 2017), better known by the legal pseudonym "Jane Roe", was the plaintiff in the landmark American lawsuit "Roe v. Wade" in 1973. The U.S. Supreme Court ruled that individual state laws banning abortion are unconstitutional. Later, McCorvey's views on abortion changed substantially; she became a Roman Catholic activist in the pro-life movement.
Document 10: American Atheists: American Atheists is a non-profit activist organization in the United States dedicated to defending the civil liberties of atheists and advocating for the complete separation of church and state. It provides speakers for colleges, universities, clubs and the news media. It also publishes books and the quarterly "American Atheist Magazine", currently edited by Pamela Whissel. The organization was founded by Madalyn Murray O'Hair in 1963, following her role in removing mandatory prayer from public schools.
Document 11: Ellen Johnson: Ellen Johnson (born 1955) is an American activist for the civil rights of atheists and for the separation of church and state in the United States. She served as the president of the organization American Atheists from 1995–2008.
Document 12: Mad (magazine): Mad (very often stylized as MAD) is an American humor magazine founded in 1952 by editor Harvey Kurtzman and publisher William Gaines, launched as a comic book before it became a magazine. It was widely imitated and influential, affecting satirical media, as well as the cultural landscape of the 20th century, with editor Al Feldstein increasing readership to more than two million during its 1974 circulation peak. As of January 2017, "Mad" has published 544 regular issues, as well as hundreds of reprint "Specials", original material paperbacks, compilation books and other print projects.
Document 13: Monika Bauerlein: Monika Bauerlein is the current CEO of "Mother Jones." Bauerlein was promoted to the position in May 2015, following the departure of Madeleine Buckingham; previously she was the magazine's co-editor. Bauerlein first came to "Mother Jones" in 2000, and has, together with Clara Jeffery (the current editor-in-chief), dramatically expanded its political and investigative reportage, as well as spearheadeding the magazine's new investigative team and Washington bureau.
Document 14: Ayaan Hirsi Ali: Ayaan Hirsi Ali (] , born Ayaan Hirsi Magan, on 13 November 1969) is a Somali-born Dutch-American activist, feminist, author, scholar, and former Dutch politician. She received international attention as a critic of Islam and advocate for the rights and self-determination of Muslim women, actively opposing forced marriage, honor violence, child marriage and female genital mutilation. She has founded an organisation for the defense of women's rights, the AHA Foundation.
Document 15: Madalyn Murray O'Hair: Madalyn Murray O'Hair ("née" Mays; April 13, 1919 – September 29, 1995), who also used multiple pseudonyms (her most preferred being M. Bible), was an American activist, founder of American Atheists, and the organization's president from 1963 to 1986. She created the first issues of "American Atheist Magazine". One of her sons, Jon Garth Murray, became the nominal president of the organization from 1986 to 1995, but she remained "de facto" president during these nine years.
ground_truth: William "Bill" Murray