Bartholomew Gill was the pen name of Mark C. McGarrity (July 22, 1943 – July 4, 2002), an Irish-American crime fiction and mystery novelist and newspaper features writer and columnist writing on nature and outdoor recreation for The Star-Ledger. He was the author of 22 mystery novels, set in Ireland, and featuring a "resourceful police detective named Peter McGarr." For his pen name, McGarrity used the name of his maternal grandfather, Bartholomew Gill, who "was a great storyteller." McGarrity wrote five novels and a work of nonfiction under his real name, and his writings for the Star-Ledger were published under his true name.
Mark C. McGarrity was born on July 22, 1943 in Holyoke, Massachusetts, McGarrity received a bachelor's degree from Brown University in Providence, Rhode Island, and a master's degree from Trinity College, Dublin. His marriage to Margaret McGarrity ended in divorce.
McGarrity died on July 4, 2002, aged 58, from injuries sustained in a fall at his Morristown, New Jersey home. He had forgotten his keys and attempted to enter his home by climbing through a window. He was survived by a daughter, Madeleine, and a brother, George. He was interred in Newton Cemetery, in Newton, New Jersey, where his gravestone identifies him by both his real name and pen name, and as "author, outdoorsman, Maddie's father".
- Under the name "Mark C. McGarrity"
- 1973: Little Augie’s Lament
- 1973: Lucky Shuffles
- 1981: A Passing Advantage
- 1990: Neon Caesar
- 1991: White Rush/Green Fire
- 1993: A Guide to Mental Retardation: A Comprehensive Resource for Parents, Teachers, and Helpers Who Know, Love, and Care for People With Mental Retardation
- Under the name "Bartholomew Gill"
- 2008: The Death of an Irish Consul
- 2004: The Death of an Irish Lass
- 2003: Death in Dublin
- 2003: The Death of an Irish Tradition
- 2002: The Death of an Irish Sinner
- 2001: The Death of an Irish Lover
- 2000: The Death of an Irish Politician
- 1998: The Death of an Irish Tinker
- 1997: The Death of an Irish Sea Wolf
- 1997: Death of a Busker King
- 1995: The Death of an Ardent Bibliophile
- 1994: Death on a Cold, Wild River
- 1993: The Death of Love
- 1990: The Death of a Joyce scholar
- 1987: McGarr and the Legacy of the Woman Scorned
- 1985: McGarr and the Method of Descartes
- 1984: McGarr and the P.M. of Belgrave Square
- 1982: McGarr and the Politician
- 1982: McGarr on the Cliffs of Moher
- 1981: McGarr at the Dublin Horse Show
- 1980: McGarr and the Sienese Conspiracy
- 1977: McGarr and the Politician’s Wife
- Gravestone for Mark C. McGarrity/Bartholomew Gill, Newton Cemetery, Newton, Sussex County, New Jersey.
- "Bartholomew Gill, 58, Author of Irish Whodunits" in The New York Times (July 11, 2002); retrieved May 3, 2013.
- "Mark McGarrity, 58; Columnist and Writer of Irish-Themed Mysteries". Los Angeles Times (Obituary). Associated Press. July 6, 2002. Retrieved April 24, 2014.