Lenny Aaron: ex-cop female private investigator and cat finder, who is obsessed with Japan, in Melbourne, Australia, by Caroline Shaw

Abby Abagnarro: television news director, in New York City, by Polly Whitney

Bea Abbot: recently widowed and trying to retire from the Abbot Agency, which specialized in cases where clients wanted to avoid police involvement, in London, England, by Veronica Heley

Ben Abbott: ex-Wall Street financier turned realtor in Newbury, Connecticut, by Justin Scott

Luke Abbott: cop in England, by Paula Gosling

Nora Abbot: operator of a ski resort in northern Arizona, by Shannon Baker

Pat and Jean Abbott (née Holly, in first two books), a husband and wife team based in San Francisco, California, who roam the world seeking a vacation without murder, by Frances Crane

Sport Abbott: in the Murder in Maine series by Mildred Davis

Amy Abel, a shy, risk-averse woman, and her domineering mother Fanny, running a travel agency specializing in adventure, in the Amy’s Travel mysteries by Hy Conrad

Tony Abernathy, the sheriff, and his wife, Theo, a quilt shop owner, in fictional Park County, in eastern Tennessee, by Barbara Graham

Billy Able: police detective in Memphis, Tennessee, by Lisa Turner

Roxana “Roxy” Abruzzo: an independent-minded niece of a Mafia boss with a teenage daughter, owner of Bada Bling Architectural Salvage, in Pittsburgh, Pennsylvania, by Nancy Martin

Jack Absolute: English army captain and spy (based on a character in Richard Sheridan’s play “The Rivals”) during the French and Indian War era (late 1750s-1760s) in colonial America and London, England, by C.C. Humphreys

Johnny Ace: DJ with a controversial phone-in radio show and who runs “Ace Investigations” in his spare time in Liverpool, England by Ron Ellis

Laura Ackroyd: reporter in Yorkshire, England, by Patricia Hall

Sam Acquillo: 50-something, retired engineer, in Southampton, Long Island, New York, by Chris Knopf

Nathan Active: Inupiak Alaska State Trooper assigned to his village of birth after being raised by a white couple in Anchorage, Alaska, by Stan Jones

Abigail Adams, the future first lady, married to a rebellious lawyer, in mid-1770s Massachusetts Colony, by Barbara Hamilton (Barbara Hambly)

Charlie “Doc” Adams: dental surgeon in Woods Hole, Massachusetts, by Rick Boyer

Charlotte Adams: 5-foot tall professional organizer, in upstate Woodbridge, New York, by Mary Jane Maffini

Gillian Adams: college history department chair in Vancouver, British Columbia, Canada, by Nora Kelly

Hilda Adams: nurse known to the police as Miss Pinkerton, by Mary Roberts RinehartJake Adams, a former Air Force intelligence and CIA officer, taking care of business in Europe and elsewhere

Jake Adams: former Air Force intelligence and CIA officer, taking care of business in Europe and elsewhere, by Trevor Scott

Samantha Adams: crime reporter in Atlanta, Georgia, by Sarah Shankman

Jean-Baptiste Adamsberg: commissioner of police (chief inspector), in Paris, France, by Fred Vargas

Max Addams: fly-fisherman and owner of Whitefork Lodge, a bed and breakfast in Vermont, by David Leitz

Adelia (Vesuvia Adelia Rachel Ortese Aguilar of Salerno), a “doctor for the dead” working for King Henry II in 12th century England, by Ariana Franklin

Irene Adler: opera star and sleuth in 19th century France, by Carole Nelson Douglas

“Mustang” Sally Adler: hard-drinking singer who comes home after 17 years as a scholar of women’s studies at the University of Wyoming, by Virginia Swift

Fernando (Nando) Aguilar: half-Indian spy working for Governor Juan Batista de Anza, in 1780s Santa Fe, New Mexico, by Pamela (Pam) Christie

Yolanda Aguillera: computer whiz, and Phil Rodriquez, a Puerto Rican ex-cop private investigator, in New York City, by Penny Mickelbury

Hallie Ahern: investigative newspaper reporter, and gambling addict, leaving Boston for Providence, Rhode Island, by Jan Brogan

Jeff Aiken: ex-government analyst, later running a cyber-security company, confronting menacing worldwide computer malfunctions, based in Washington, DC, by Mark Russinovich

Martin Ainsworth: in England, by Michael Underwood

Sugawara no Akitada: sleuth in 11th century Japan by I.J. Parker

Simon Alastair: gay bookstore owner and amateur sleuth in fictional Dickens Junction, Oregon, by Christopher Lord

Jack Albany: small-time actor mistaken for a Mafia hit-man, in New York City, by John Godey

Karl Alberg: staff sergeant in the Royal Canadian Mounted Police in Sechelt, British Columbia, Canada, by L.R. Wright

Flavia Albia: adopted daughter of Marcus Didius Falco, born in Britain, working as a private investigator during the reign of Emperor Domitian, in ancient Rome, by Lindsey Davis

Lottie Albright: editor for the county historical society in a small town in western Kansas, by Charlotte Hinger

Louisa May Alcott: amateur sleuth before becoming a famous author, in pre-Civil War Boston, Massachusetts, by Anna Maclean

Rev. Claire Aldington: psychologist and Episcopal priest at St. Anselm’s, in Manhattan, New York, by Isabelle Holland

A.J. (Anna Jolie) Alexander: 30-something marketing consultant in Manhattan, New York, in the Yoga mysteries, by Diana Killian

Brandy Alexander: reporter returning home after four years in L.A, to Philadelphia, Pennsylvania, by Shelly Fredman

Rachel Alexander: private investigator and dog trainer, and Dashiell, her pit bull, in New York City, by Carol Lea Benjamin

Khalid Ali: Detective Sergeant, and John Handford, Detective Inspector, in Bradford, Yorkshire, England, by Lesley Horton

Mercy Allcutt: former Boston Brahmin, working for a down-on-his luck private investigator, in 1920s Hollywood, California, by Alice Duncan

Steve Allen and Jayne Meadows, celebrity crime-solvers in Los Angeles, California, by Steve Allen

Roderick Alleyn: second son of a baronet and police inspector in London, England, by Ngaio Marsh

Owen Allison: US Department of Transportation investigator in West Virginia, by John Billheimer

Gabriel Allon: art restorer and Israeli secret agent, by Daniel Silva

Carlos Tejada Alonso y Leon: sergeant in Guardia Civil in 1930s and 1940s Madrid, Spain, by Rebecca Pawel

Vinnie Altobelli: ex-cop coronary survivor and private investigator, in San Bernadino, California, by Milton Bass

David Alvarez: police detective in El Paso, Texas, by Aileen Schumacher

Enrique Alvarez: police inspector in Mallorca, Spain, by Roderic Jeffries

Selena Alvarez and Regan Pescoli, police detectives in Pinewood County, Montana, by Lisa Jackson

Angelina Amalfi: food columnist and restaurant reviewer, in San Francisco, California, by Joanne Pence

Tito Amato: sold as a child to be a castrato opera singer, in 18th century Italy, in the Baroque Mystery series by Beverle Graves Myers

Amerotke: Chief Judge in Thebes, Egypt, by P.C. Doherty

Simon Ames and David Becket, secret agents for Queen Elizabeth, in 1580s England, by Patricia Finney (P.F. Chisholm)

Otto “Big Red” Amlingmeyer and his brother Gustav “Old Red” in 1890s Montana, cowboys who got interested in being detectives after reading a Sherlock Holmes story, in the Holmes on the Range series, by Steve Hockensmith

Dewey Andreas: former Delta officer fighting against international terrorists, by Ben Coes

Anders: one-legged police inspector, specializing in anti-terrorism, in Italy, by Marshall Browne

Tad Anders: Polish-British agent in England, by Ted Allbeury

Annie Anderson: tabloid feature writer and fashion editor at Handbag Magazine, based in London, England, by Sam Baker

Mali Anderson: black female ex-NYPD cop, turned sleuth in Harlem, New York, by Grace F. Edwards

Shifty Lou Anderson: professional magician and horseplayer, in southern California, by William Murray

Sophie Anderson: transplanted Australian who has premonitions working as an FBI profiler, based in Quantico, Virginia, by P.D. Martin

Will Anderson, working in his father’s electric car company in 1910 Detroit, Michigan, by D.E. Johnson

Margit Andersson: freelance Danish translator in Seattle, Washington, by Tiina Nunnally

Avery Andrews: 30-something lawyer, in South Carolina, by Cathy Pickens

Emily Andrew: tour guide based in Iowa, in the Passport to Peril mysteries by Maddy Hunter

Antoine Andrieux: a young Basque in Paris, France, by Tonino Benacquista

Elise Andrioli: left blind mute and quadriplegic after a terrorist bomb explosion that killed her fiancé, in Northern Ireland, by Brigitte Aubert

Fitzroy Maclean Angel: trumpet-playing taxi driver in London, England, by Mike Ripley

Michael Angel: detective inspector in Bromersley, South Yorkshire, England, by Roger Silverwood

Eve Angelotta: 30-ish former dancer, now chef at her family’s Italian restaurant outside Philadelphia, Pennsylvania, by Shelley Costa

Mark Angelotti: psychologist who became blind due to a genetic disorder, in Chicago, Illinois, by Lynne Raimondo

Ronald Anglesea: private investigator in England and Scotland, by George Milner

Mici Anhalt: Crime Victims’ Compensation Board in New York City, by Lillian O’Donnell

Thomas Ansell: London attorney who travels to British cathedral towns during the Victorian era, by Philip Gooden

Father Anselm: lawyer turned monk, in Larkwood Priory, England, by William Brodrick

Callie Anson: newly ordained Anglican cleric, her boyfriend Mark Lombardi, a police officer, and DI Neville Stewart, in London, England, by Kate Charles

Joseph Antonelli: criminal lawyer in Portland, Oregon, by D.W. Buffa

Lady Aoi: lady-in-waiting, trained in Chinese healing arts, in the late Heian period (1020s), at the Imperial Palace, Kyoto, Japan, by Ann Woodward

Wang Anzhuang: Public Security Bureau inspector, in Beijing, China, by Christopher West

Juliet Applebaum: public defender turned stay-at-home mom, in Los Angeles, California, in the Mommy Track mysteries, by Ayelet Waldman

John Appleby: inspector at Scotland Yard in London, England, by Michael Innes

Molly Appleby: writer for Collector's Weekly magazine, in North Carolina and Virginia, in the Collectible mysteries, by J.B. Stanley

Belle Appleman: Jewish immigrant and garment worker during the Great Depression, in Boston, Massachusetts, by Dorothy and Sidney Rosen

Lady Susanna Appleton: herbalist in Elizabethan England, by Kathy Lynn Emerson

Reverend Mother Aquinas, in 1920s Cork, Ireland, by Cora Harrison

Mas Arai: Japanese-American Hiroshima survivor, gardener in Los Angeles, California, and sleuth, by Naomi Hirahara

Araki: investigative journalist in Tokyo, Japan, by Guy Stanley

Carlo Arbati: poet and police inspector, by John Spencer Hill

Annabelle Archer: wedding planner in Washington, DC, by Laura Durham

Lew Archer: ex-cop and private investigator, in Los Angeles, California, by Ross MacDonald

Owen Archer: medieval spy for the Archbishop, in Wales, by Candace M. Robb

Arcturus: the Roman governor’s doctor and investigator, in 83 AD Londinium, Britain, by Kelli Stanley

Kathryn Ardleigh: American author who moves to Victorian Dedham, England, by Robin Paige

Tom Aragon: Hispanic lawyer, by Margaret Millar

Jan Argand: police commissioner in Brabt, a fictional European country, by Julian Rathbone

Jonathan Argyll: English art dealer, and Flavia di Stefano, of the Art Theft Squad, in Rome, Italy, by Iain Pears

Aristotle, the philosopher, and Stephanos, a former student, in 330s BCE Athens under the rule of Alexander, by Margaret Doody

Simon Ark: 2000 year old Coptic priest, in New York City, by Edward D. Hoch

Allie Armington: lawyer in Texas by Louise Gaylord

Israel Armstrong: Jewish vegetarian from London, in charge of a mobile library in the village of Tumdrum, Northern Ireland, in the Mobile Library mysteries, by Ian Sansom

Sarah Armstrong: criminal profiler lieutenant in the Texas Rangers, and a recently widowed mother, based in Houston, Texas, by Kathryn Casey

Henry Arnold: Scotland Yard inspector, and Desmond Merrion, a military intelligence officer who becomes a private detective, in England, by Miles Burton (John Rhode)

Sister Jane Arnold: 70-year-old Master of the Fox Hunt in Virginia, by Rita Mae Brown

Jessie Arnold: dog sled racer, and Sergeant Alex Jensen, a state trooper, in Anchorage, Alaska, by Sue Henry

Spencer Arrowood: Appalachian sheriff, by Sharyn McCrumb

Jacob Asch: Jewish-Episcopal ex-reporter private investigator in Los Angeles, California, by Arthur Lyons

Jolene Asdale: owner of a sports car boutique, in the fictional tourist town of Wachobe in the Finger Lakes region of New York, in the Broken Vows mysteries by Lisa Bork

Benny Ashe: retired Mob boss, in Coral Sands, Florida, in the Old Gang of Mine series, by Richard F. West

Kristin Ashe: amateur sleuth in Denver, Colorado, by Jennifer Jordan

James Asher: professor and one-time spy, in London, England, by Barbara Hambly

Steve Asher: middle-school teacher, in Massachusetts, by Al Blanchard

Aaron Asherfield: cynical investigator with three ex-wives, in San Francisco, California, by David Berlinski

Carol Ashton: lesbian detective inspector in Sydney, Australia, by Claire McNab

Lady Emily Ashton: young and recently widowed, in Victorian London, England by Tasha Alexander

Peter Ashton: secret agent in the British SIS, by Clive Egleton

Demetrios Askiates: former bounty hunter and bodyguard, in service to the Byzantine Emperor in late 11th century Constantinople, in the First Crusade trilogy, by Tom Harper (Edwin Thomas)

Getorius Asterlus: surgeon, and Arcadia Asterlus, his wife, in 5th century Italy, by Albert Noyer

Brother Athelstan: Dominican monk in 14th century London, England, by Paul Harding

Ray Attla: Inupiat police officer, returns to his native home after growing up in Anchorage, Alaska, by Christopher Lane

Nick Atwell: police sergeant at Scotland Yard, and detective constable Clare Reynolds, in London, England, by Michael Underwood

Lauren Atwill, a screenwriter, and private investigator Peter Winslow, based in 1940s Hollywood, California, by Sheila York

Dr. David Audley: historian and spy in England, by Anthony Price

Cat Austen: single-mom reporter, and Victor Cardenas, a police detective, in Atlantic City, New Jersey, by Jane Rubino

Jaine Austen: freelance writer in Los Angeles, California, by Laura Levine

Jane Austen: famous author in England, by Stephanie Barron

Kate Austen: single mother in Walnut Hills, California, by Jonnie Jacobs

Beth Austin: English professor at Midwestern University in 1940s Illinois, by Edith Skom

Jack Austin: golf player on the PGA circuit by John Corrigan

Kurt Austin: in the underwater exploration series, NUMA Files, by Clive Cussler and Paul Kemprecos

Max Austin: ex-FBI agent, now private investigator also interested in astronomy and things cosmic, in Kansas, by Mark Bouton

William Austen: chief inspector, later Superintendent, at Scotland Yard, in London, England, by Anne Hocking

Ellie Avery: Air Force wife and professional organizer, in the Mom Zone mysteries by Sara Rosett

Avraham Avraham: police detective in Tel Aviv, Israel, by D.A. Mishani

Mick “Brew” Axbrewder: unlicensed private investigator in Puerta del Sol, California, by Reed Stephens

Yael Azoulay: behind-the-scenes negotiator for the United Nations who goes rogue, by Adam LeBor