Milo Kachigan: policeman, and Helen Sorby, a social worker, in 1905 Pittsburgh, Pennsylvania, by Karen Rose Cercone

Skin Kadash: homicide detective (later ex-cop) in Portland, Oregon, by Bill Cameron

Ariel Kafka: police inspector in the Violent Crime Unit and one of only two Jewish cops in the country, in Helsinki, Finland, by Harri Nykänen

Maria Kallio: police inspector in Espoo, Finland, by Leena Lehtolainen

Alison Kaine: lesbian police officer in Denver, Colorado, by Kate Allen

Andreas Kaldis: former Athens homicide detective, now the new police chief on Mykonos Island, Greece, by Jeffrey Siger

Ben Kamal: member of the new Palestinian police force on the West Bank, and Danielle Barnea, a Shin Bet (Israel’s FBI) agent in Israel, by Jon Land

Dmitri Kameron: lawyer in Kursk, Russia, by Michael Pearce

Kimo Kanapa’aka: gay police detective in Honolulu, Hawaii, by Neil Plakcy

Andy Kane: by Carter Brown

Brian Kane: private investigator in 1950s Hollywood, California, by Jack Bludis

Karl Kane: private investigator in Belfast, Northern Ireland, by Sam Millar

Nik Kane: 50-something ex-Anchorage cop, ex-con, and ex-husband, in Alaska, by Mike Doogan

Ken Karasik: billionaire born in Communist Bosnia, devoted to securing freedom for the Slavs in the Balkans, by Kenin Spivak and Julie Christyn

Dan Kardon: Boston attorney who uncovers corruption and murder in a quiet, working-class community near Cape Cod, Massachusetts, by Jamie Katz

Kitty Karlyle: gourmet chef for pets, in Los Angeles, California, by Marie Celine

Roger “Butch” Karp: Criminal Courts Bureau chief, and Marlene Ciampi, assistant District Attorney in 1970s New York City, by Robert K. Tanenbaum

Mary Magruder Katz: half Jewish, half Southern Baptist criminal defense attorney, in Miami, Florida, by Barbara Levenson

Sophie Katz: half-Black, half-Jewish mystery writer, in San Francisco, California, by Kyra Davis

Sarah Kauffman: an artist who paints murals on barns in her Amish community, and Nate MacKensie, an Ohio state arson inspector, in the Home Valley Amish series by Karen Harper

Sarah Kaufman: Jewish probate court official in 1920s Toledo, Ohio, later visiting Dayton, Tennessee, by Ona Russell

Frank Kavanagh: detective inspector, and later, detective constable Jane Salt, in Birmingham, England, by David Armstrong

Brett Kavanaugh, running a tattoo shop in Las Vegas, Nevada, in the Tattoo Shop series, by Karen E. Olson

Nick Kavanaugh: a cop with a dark side, and his wife, Kate, a distinguished lawyer from an old southern Niceville family, by Carsten Stroud

Storm Kayama: attorney in Honolulu, Hawaii, by Deborah Turrell Atkinson

Kemal Kayankaya: private investigator of Turkish background, in Frankfurt, Germany, by Jakob Arjouni

Simon Kaye: private investigator in New York City, by Hillary Waugh

Matsuyama Kaze: 17th century rogue samurai in rural Japan, by Dale Furutani

Ryan Kealey: ex-CIA agent and former Special Forces soldier, dealing with terrorists in the US, by Andrew Britton

Maggie Kean: art teacher and sculptor in the high country of Colorado, by Nageeba Davis

Owen Keane: ex-seminarian and law firm researcher, in Boston, Massachusetts, by Terence Faherty

Pepper Keane: former federal prosecutor, now a private investigator, in Colorado, by Mark Cohen

Kevin Kearnes: chief of police of the fictional coastal town of Cutter Point, Oregon, near the California border, and later an agent with Homeland Security in Portland, Oregon, and Thud Compton, a police sergeant, later chief, by Kenneth R. Lewis

Daniel Kearney Associates: auto repo and skip-tracing firm, in San Francisco, California, by Joe Gores

Frank Kearney and Jose Phelps, veteran Washington DC, cops by Robert Andrews

Sara (Sally) Keate: nurse in New York, by Mignon G. Eberhart

Kyra Keaton: aristocratic lady private investigator running her own agency in 1899-1907 Washington, DC, by Teona Tone

Lloyd Keaton: local sportswriter with a gambling addiction, in fictional Menkenburg, a city in east-central Ohio, by John Billheimer

Michael Keefe: photographer with DEPOE (Defense Photo Operations Executive), mostly in Vietnam, by Michael Wolfe

Rose Doyle Keefe: working to support her family in a shipyard in 1942 New York City, in the Rosie the Riveter series by Amy Patricia Meade

John Keegan: homicide detective in New York City, by John Misak

George Keene: spy in William Pitt’s intelligence service during England’s war with France in the 1790s, by Derek Wilson

Jayne Keeney: 30-something Australian, former English teacher and private investigator, in Bangkok, Thailand, by Angela Savage

Ben Kella: police sergeant and hereditary spiritual peacekeeper of the Lau people, and Sister Conchita, a 20-something American nun, in the 1960s Solomon Islands, by Graeme Kent

Art Keller: DEA agent dealing with a large cast of characters in the drug trade based in Mexico, by Don Winslow

Jack Keller: bounty hunter in Fayetteville, North Carolina, by J.D. Rhoades

Joe Keller: NYPD homicide detective in New York City, by Nelson DeMille

John Keller: hit-man in New York City, by Lawrence Block

Konstantin Keller: retiring detective inspector, in Munich, Germany, by Hans Hellmut Kirst

Sarah Kelling: socially connected wife of Max Bittersohn, art detective, in Boston, Massachusetts, by Charlotte MacLeod

Benson Kellogg: lawyer who inherits a town in New Mexico, and fights to save it, by Bart Spicer

Michael Kells by Peter Cheyney

Clovis Kelly: ex-NYPD homicide detective and TV crime consultant, in New York City, by Jacqueline Babbin

Eloise Kelly: Harvard grad student writing her Ph.D. dissertation on spies of the late 18th and early 19th century, in a romantic thriller series by Lauren Willig

Homer Kelly: lawyer and former police lieutenant, now a Harvard professor, in Cambridge, Massachusetts, by Jane Langton

Irene Kelly: newspaper reporter in southern California, by Jan Burke

Jack Kelly and Charles Carr: seasoned, tough Secret Service agents after counterfeiters, starting in Los Angeles, California, and Washington, DC, by Gerald Petievich

Jane Kelly: reluctant private investigator, and her pug, The Binkster, in Lake Chinook, Oregon, by Nancy Bush

Keira Kelly: half-breed descendant of a powerful paranormal family living among humans in Rio Seco, Texas, by Maria Lima

Liza Kelly: former publicist in Hollywood, now a sudoku columnist for a paper in her hometown of Maiden’s Bay, Oregon, in the Sudoku mysteries by Kaye Morgan

Maggie Kelly: writer of historical romances, dumped by her publisher, starts writing mysteries, in New York City, by Kasey Michaels

Michael Kelly: ex-cop private investigator, in Chicago, Illinois, by Michael Harvey

Neil Kelly: professor of English at a New England college, by S.F.X. Dean

Patrick Kelly: with underworld connections, and Kate Burrows, a detective inspector, in the East End of London, England, by Martina Cole

Virginia Kelly: black lesbian stockbroker in Chicago, Illinois, by Nikki Baker

Casey Kellogg: ex-surfer college-grad detective, teamed with Al Krug, a seasoned cop of the old school, in Santa Monica, California. by Carolyn Weston

Kelsey: detective inspector, later chief inspector, and detective Lambert, in a village somewhere in England, by Emma Page

Jason Keltner: composer and ex-spy, in Los Angeles, California, by Keith Snyder

Lennox Kemp: disbarred solicitor working as a detective, in London England, by M.R.D. Meek

Killian Kendall: gay high school sleuth in Maryland, by Josh Aterovis

Kylie Kendall: lesbian manager of a pub in tiny Wollegudgerie, Australia, who inherits 51% of her father's private detective agency in Los Angeles, California, by Claire McNab

William Kendall: chief troubleshooter for the Joint Chiefs of Staff, and his friend Lt. Colonel Aaron Eisenberg, here and there in the world, by Philip Chase (Philip Friedman)

Veil Kendry: painter and adventurer in New York City, by George Chesbro

Beth Kennedy: recently divorced mother of two, running the Children’s Bookshelf bookstore and serving as PTA secretary, in Rynwood, near Madison, Wisconsin, by Laura Alden

Christy Kennedy: Irish-born Detective Inspector of Camden CID in England, by Paul Charles

Jerry Kennedy: criminal defense attorney in Boston, Massachusetts, by George V. Higgins

Jill Kennedy: forensic psychologist, and Max Trentham, a detective chief inspector and her ex-lover, in the village of Kelton Bridge, Lancashire, England, by Shirley Wells

Kate Kennedy: senior citizen in south Florida, by Nora Charles (Noreen Wald)

Mike Kenny: police inspector in Dublin, Ireland, by Eilís Dillon

Charlotte Kent: freelance writer in fictional Pelican Rock, Mendocino County, California, by Mary Kittredge

Miss Dido Kent: 35-year-old amateur sleuth, starting in 1805 Regency England, by Anna Dean

Simon Kenworthy: hard-working detective inspector, later superintendent, with Scotland Yard, in London, England, by John Buxton Hilton

Patrick Kenzie and Angela Gennaro, private investigators in Dorchester, Massachusetts, by Dennis Lehane

Joe Keough: NYPD detective who moves to St. Louis, Missouri, by Robert J. Randisi

Alison Kerby: guesthouse owner with two unexpected guests (ghosts) in her newly acquired Jersey Shore Victorian, in the Haunted Guesthouse mysteries, by E.J. Copperman (Jeffrey Cohen)

Helen Keremos: 40-something lesbian private investigator and former intelligence operative based in Vancouver, British Columbia, also operating in Toronto, Ontario, Canada, and elsewhere, by Eve Zaremba

Kevin Kerney: ex-chief of detectives in Santa Fe, New Mexico, by Michael McGarrity

Constable Kerr and inspector Robert Fusil in the fictious seaside Fortrow, England, by Peter Alding (Roderic Jeffries)

Maeve Kerrigan: ambitious young detective constable, in London, England, by Jane Casey

Daniel “Red” Kerry by Sax Rohmer

Julian Kestrel: dandy-about-town in 1820s London, England, by Kate Ross

Jean-Claude Keyes: actor, writer, and amateur sleuth, at the Shakespeare Festival in Stratford, Ontario, Canada, by Bevan Amberhill

Yusuf Khalifa: police detective in Luxor, Egypt, by Paul Sussman

Iona Khan: feisty detective constable in the Counter Terrorism Unit in Manchester, England, by Chris Simms

Rafi Khan: a London fund manager, and detective inspector Kate Adams of the City’s economic crime unit, by Piers Venmore-Rowland

Truman Kicklighter: retired reporter, in St. Petersburg, Florida, by Kathy Hogan Trocheck

Kidd: a computer whiz, and LuEllen, a thief in Minneapolis, Minnesota, by John Sandford

Bamson Kiet: police superintendent in an imaginary country in the Far East, by Gary Alexander

Edie Kiglatuk: former polar bear hunter and the best guide in her isolated Inuit community in the Canadian Arctic, by M.J. McGrath

Joanne Kilbourn: political science professor in Regina, Saskatchewan, Canada, by Gail Bowen

Kerry Kilcannon: senator, then President of the USA, in Washington, DC, by Richard North Patterson

Nolan Kilkenny: ex-Navy SEAL, working at his father's online research firm in Michigan, by Tom Grace

Sal Kilkenny: single mother private eye in Manchester, England, by Cath Staincliffe

Johnny Killain: hotel detective at the Hotel Duarte and part-time private investigator, in New York City, by Dan J. Marlowe

Coley Killebrew: ex-jockey turned restaurant owner, in southern California, by Bill Shoemaker

Daniel Killstraight: young Comanche sent off to the Carlisle School for seven years before returning to the Comanche Nation to serve as a policeman, by Johnny D. Boggs

Francis Xavier Killy: “The Inquisitor,” a lay brother investigator for the Vatican, by Simon Quinn (Martin Cruz Smith)

Miss Dimple Kilpatrick: a longtime first-grade teacher during World War II, in Elderberry, Georgia, by Mignon F. Ballard

Felix Kimmel: police inspector in rural Austria, by John Brady

Alex Kincaid: a librarian, and Nora McKee, a college professor, fighting shadowy government agents using time travel, by T.J. MacGregor

Annie Kincaid: reformed art forger now in the faux finishing business, in the Art Lover’s mysteries by Hailey Lind

Ben Kincaid: attorney in Tulsa, Oklahoma, by William Bernhardt

Biff Kincaid: stand-up comedian turned amateur sleuth in Los Angeles, California (right below the Hollywood sign) by Dan Barton

Carnegie Kincaid: wedding planner in Seattle, Washington, by Deborah Donnelly

Duncan Kincaid: Scotland Yard superintendent, and Gemma James, a sergeant, in London, England, by Deborah Crombie

Emily Kincaid, a recently divorced reporter and failed mystery writer, and Dolly Wakowski, a deputy, in rural Leetsville, in northern Michigan, by Elizabeth Kane Buzzelli

Libby Kincaid: magazine photographer in New York City, by Kerry Tucker

Louis Kincaid: biracial cop in Loon Lake, Michigan, by P.J. Parrish

Sam Kincaid: chief of the Special Investigations Branch of the Department of Corrections, and Lt. Kate McConnell, a homicide detective, in Salt Lake City, Utah, by Michael Norman

Samantha Kincaid: Deputy District Attorney in Portland Oregon, by Alafair Burke

Daniel Kind: retired Oxford historian, and Detective Chief Inspector Hannah Scarlett of the Cold Case Squad, in the Lake District of England, by Martin Edwards

Bailey King, leaving New York to take over Swissmen Sweets, her Amish grandparents’ candy shop, in Harvest, Ohio, in the Amish Candy Shop mysteries by Amanda Flower

Jack King: former FBI profiler running a hotel with his wife, in Tuscany, Italy, by Michael Morley

Sean King and Michelle Maxwell, Secret Service agents, in Washington, DC, and Virginia, by David Baldacci

Willow King: romance novelist in London, England, by Natasha Cooper

Lucy Kingsley: artist, and David Middleton-Brown, a solicitor, in London, England, and the Church of England, in the Book of Psalms mysteries by Kate Charles

Sarah Kingsly: a white homicide detective, and her new partner Angel Johnson, a black detective, in Dallas, Texas, by Maryann Miller

Lawrence Kingston: retired botany professor in England, in the English Garden mysteries, by Anthony Eglin

Palmer Kingston: Pulitzer-winning reporter for the Marlinsport Tribune, and Alice Jane (A.J.) Egan, his lover who writes for the competing New Seville Times, set mostly in Florida, by Matt & Bonnie Taylor

Cate Kinkaid: fledgling private investigator in Eugene, Oregon, by Lorena McCourtney

John “JP” Kinkaid: member of Blacklight, a legendary British rock group, by Deborah Grabien

Kate Kinsella: nurse and medical examiner in England, by Christine Green

Jacqueline Kirby: middle-aged librarian, by Elizabeth Peters

Simon Kirby-Jones: gay American writer who became a vampire in Houston, now living in Snupperton Mumsley, a small village in England, by Dean James

Millie Kirchner: 20-something single mother, student, and nursing home aide, in Richardson, Texas, in the Deadly Past mysteries by Marion Moore Hill

Charles Kirk: a general, head of British Foreign Office Intelligence, mostly in England, by John Blackburn

Devlin Kirk: ex-secret service agent and owner of high-tech security company, in Denver, Colorado, by Rex Burns

Fran Kirk: ex-battered wife turned private investigator working for an insurance company, in Buffalo, New York, by Ruthe Furie

Steven Kirk: burned-out CIA agent, in Charlottesville, Virginia, by Doug Hornig

Kirsten: owner of the Wild Onion, Ltd, a private detective agency, and her husband Dugan, a lawyer, in Chicago, Illinois, by David J. Walker

Matteesie Kitologitok, “the great brain of Arctic crime,” an Inuit inspector in the Royal Canadian Mounted Police, based in the Northwest Territories of Canada, by Scott Young

Dylan Klein: insurance investigator in New York City, by Reed Farrel Coleman

Frieda Klein: psychotherapist in London, England, by Nicci French

Katy Klein: former psychologist turned astrologer who lives in Ottawa, Canada, by Karen Irving

Sam Klein: street-wise Jewish immigrant and private investigator, in 1911-1919 Winnipeg, Manitoba, Canada, by Allan Levine

Chris Klick: dropout-songwriter turned private investigator in Idaho, by Wendell McCall (Ridley Pearson)

Abby Knight: law school drop-out and the owner of Bloomers Florists in New Chapel, Indiana, in the Flower Shop mysteries, by Kate Collins

Jerry Knight: talk show host, and Jane Day, a newspaper reporter, in Washington DC, by Ron Nessen and Johanna Neuman

Louie Knight: private investigator in Aberystwyth, Wales, in a comic Welsh noir series by Malcolm Pryce

Michael Knight: a young attorney who gets a job with his mentor, legendary trial attorney Lex Devlin, in Boston, Massachusetts, by John F. Dobbyn

Micky Knight: lesbian private investigator in New Orleans, Louisiana, by J.M. Redmann

Philip Knight: New York PI, and his brother, Roger Knight, a philosophy professor in South Bend, Indiana, “The Brothers Knight,” in the Notre Dame mysteries by Ralph M. McInerny

Rachel Knight: 30-something deputy DA in the Special Trials Unit, in Los Angeles, California, by Marcia Clark

Thomas Knight: disgraced high-school English teacher from Evanston, Illinois, traveling around confronting puzzling conspiracies, by A.J. Hartley

Deborah Knott: district judge in North Carolina, by Margaret Maron

Sophie Knowles: math professor at Henley College, in Massachusetts, by Ada Madison (Camille Minichino)

Daniel Knox: American Egyptologist and dive instructor, by Will Adams

Fiona Knox, after losing her fiancé and her flower shop, inherits her godfather’s cottage and magical garden, in Duncreigan, Scotland, in the Magic Garden mysteries by Amanda Flower

John Knox, an American Iraqi war veteran with an import/export business, and Grace Chu, an American-educated Chinese forensic accountant, and working together as freelance undercover operatives around the world in the Risk Agent series by Ridley Pearson

Anders Knutas: police inspector on Gotland Island, Sweden, by Mari Jungstedt

Edward Koch: Mayor of New York City by Edward Koch

Atticus Kodiak: bodyguard in New York City, by Greg Rucka

Father Robert Koesler: Catholic priest in Detroit, Michigan, by William X. Kienzle

Bruce Kohler: recovering alcoholic in Manhattan, New York City, by Elizabeth Zelvin

Herman Kohler: Gestapo agent, based in 1940s Paris, France, and Jean-Louis St. Cyr, an officer in the French Sûreté Nationale, by J. Robert Janes

Jason Kolarich: lawyer in Chicago, Illinois, by David Ellis

Kathy Kolla: young Scotland Yard detective, and David Brock, her mentor, in London, England, by Barry Maitland

Hayden Konig: police chief, and choir director and organist at St. Barnabas Episcopal Church, in the Appalachian town of St. Germaine, North Carolina, by Mark Schweizer

Alexei Korolev: captain in the militia’s Criminal Investigation Division under Stalin, in 1930s Moscow, Russia, by William Ryan

Anni Koskinen: ex-cop private investigator, in Chicago, Illinois, by Barbara Fister

Sakari Koskinen: police officer in Tampere, Finland, by Seppo Jokinen

Leigh Koslow: ad copywriter in Pittsburgh, Pennsylvania, by Edie Claire

Karen Kovac and Terry Flynn, special squad detectives in Chicago, Illinois, by Bill Granger

Sam Kovac: hard-boiled police detective, and his wisecracking partner Nikki Liska, in Minneapolis, Minnesota, by Tami Hoag

Ferenc Kolyeszar, Emil Brod, Brano Sev, and other police and intelligence agents in Communist-era Eastern Europe, by Olen Steinhauer

Milt Kovak: sheriff in Prophesy County, Oklahom, by Susan Rogers Cooper

Loretta Kovacs and Frank Marvelli, members of a parole violators search team, in New Jersey, by Anthony Bruno

Takeshi Kovacs: semi-immortal antihero in the 25th century, by Richard Morgan

Spaceman Kowalski and Blue Maguire, Vietnam vets and cops, in Los Angeles, California, by Teri White

Thea Kozak: educational consultant in Massachusetts, by Kate Flora

Joe Kozmarski: private investigator in Chicago, Illinois, by Michael Wiley

Jonathan Kraag: former FBI profiler now a PI, Director of Security, ADMS in Ravensburg, Illinois, by T.A. Stone

Theda Krakow: cat-loving, freelance writer in Cambridge, Massachusetts, by Clea Simon

Josh Krales: crime reporter for the New York Event, in New York City, by Heywood Gould

Tromp Kramer: Afrikaner police detective, and Mickey Zondi, a Bantu police sergeant, in Trekkersburg, South Africa, by James McClure

Willi Kraus, a decorated soldier in WWI, and the most celebrated Jewish detective in Weimar Germany, by Paul Grossman

Stan Kraychik: gay hairdresser in Boston, Massachusetts, by Grant Michaels

Tom Kreuger: biologist working for the Bureau of Land Management in a small town in a western state of the US, by C.F. Button

Professor Kreutzemark: in Switzerland and Spain, by Francis Beeding

Harvey Krim: police detective in New York City, by E.V. Cunningham

Kolbjorn Kristiansen (K2), a detective inspector, and his wheelchair-bound assistant Patricia, starting in late 1960s, Oslo, Norway, in the K2 and Patricia series by Hans Olav Lahlum

Al Krug: seasoned cop of the old school, and Casey Kellogg, an ex-surfer college-grad detective, in Santa Monica, California. by Carolyn Weston

Dan Kruger: 30-something ex-cop and former rock musician, now a private investigator, in Chicago, Illinois, by Michael Cormany

Herbie Kruger: senior staffer in British Intelligence, in England, by John Gardner

Kimmey Kruse: stand-up comedian in Austin, Texas, by Susan Rogers Cooper

Jakob Kuisl, the hangman of Schongau, his clever and headstrong daughter Magdalena, and Simon Fronwieser, the son of the town doctor, in mid-17th century Bavaria, Germany, by Oliver Pötzsch

Robert Kurland: army major wounded at Waterloo, and his childhood friend and housekeeper, Lucy Harrington, the rector’s daughter, in Kurland St. Mary, in Regency England, by Catherine Lloyd

Ivan Kuvakin: bureaucrat in Moscow and elsewhere in Russia, by Anthony Olcott

Handsome Kuzak and Bingo Riggs, photographers traveling across the USA, by Craig Rice

Cato Kwong: Detective Senior Sergeant in Western Australia, by Alan Carter