La Batarde, Magdalene: a whoremaster in 1100s London, England by Roberta Gellis

Devonie Lace: by Gina Cresse

Captain Gabriel Lacey: former cavalry officer in Regency-era London, England, by Ashley Gardner

Lacey, Jordan: an ex-cop, start-up private investigation, in Latching, England by Stella Whitelaw

Lacey, Meg: a private investigator in Vancouver, British Columbia, Canada by Elisabeth Bowers

Tim Lacy: security expert investigating crime and fraud in the international art world, by Derek Wilson

Ladderback, Shep: an aging obituary writer for a tabloid in Philadelphia, Pennsylvania by Bill Kent

Laguerre, Dee: a Bureau of Land Management ranger in Nevada by Kirk Mitchell

Laidlaw, Jack: police detective in Glasgow, Scotland by William McIlvanney

Laird, Andrew: international marine insurance claim investigator by Robert MacLeod

Honey (Honoria Potterton-Phipps) Laird: party-girl turned detective sergeant, then inspector, in Edinburgh, Scotland, by Gerald Hammond

Lake, Barrett: a history teacher turned private investigator in Berkeley, California by Shelley Singer

Kerry Lake: detective in England, by Bill James

Lake, Lavinia  and Tobias March, lovers and partners-in-crime investigators, in Regency London, England by Amanda Quick

Lamb, Inspector Ernest: police inspector in London, England by Patricia Wentworth

Lambert, Superintendent John: a policeman and golf enthusiast in Oxford, England by J. M. Gregson

Lambros, Julia: cafe owner and part-time speech pathologist in Delphi, Georgia by Takis and Judy Iakovou

Lambros, Nick: Greek immigrant and cafe owner in Delphi, Georgia by Takis and Judy Iakovou

Lamerino, Gloria: a 50-something physicist in Revere Beach, Massachusetts by Camille Minichino

Land, Marty: by David Alexander

Landon, Arnold: a medieval architecture expert and researcher in Northumberland, England by Roy Lewis (b.1933)

Lane, Drury: a Shakespearian actor retired due to progressive deafness, on the Hudson River, New York by Barnaby Ross

Lane, Paul: detective working out of the Nineteenth Precinct in New York by Richard Lockridge

Langdon, Skip: policewoman in New Orleans, Louisiana by Julie Smith

Lange, Lizbet: heiress and ex-waitress in California by L.L. Thrasher

Langley, Ingrid: novelist and British Agent by Margaret Duffy

Langslow, Meg: decorative blacksmith in a southern town by Donna Andrews

Lanier, Jane: a former journalist turned private investigator in Portland, Oregon by Katy King

Lansing, Cliff: single-father and part-time rancher-sheriff in New Mexico by Micah S. Hackler

Larch, Marian: NYPD officer in New York, New York by Barbara Paul

Lou Largo: private investigator in New York City, by William Ard

Cas Larkin: sheriff in fictional Pine County, Tennessee, in the Maryville series by Jackie Griffey

Stephen Larkin: London tabloid journalist whose wife and baby were murdered, now back in his hometown of Newcastle, England, by Martyn Waites

LaRue, Charlotte: a maid in New Orleans, Louisiana by Barbara Colley

Geri LaRue: hearing-impaired 20-something, and other newspaper reporters in San Francisco, and elsewhere in California, by Bonnie Hearn Hill

Lassiter, Jake: ex-linebacker turned lawyer in Miami, Florida by Paul Levine

Lassiter, Quannah: a Lakota-speaking special investigator for the Texas Rangers, in Nickleberry, Texas by Kat Goldring

Latham, Grace: an attractive widow in Washington D. C. by Leslie Ford

Latimer, Charles: British university lecturer turn detective novelist in Turkey by Eric Ambler

Latimer, Charles and James: the ghosts of cousins killed in the Franco-Prussian War by Manning Coles

Latymer, John: former copper and literary tour guide for groups of American Tourists in Great Britain by Judith Cook

Laurance, Annie: mystery book store owner in Broward's Rock, South Carolina by Carolyn G. Hart

Laurano, Lauren: a lesbian private investigator in Manhattan, New York by Sandra Scoppettone

Commissaire Laviolette: police detective in Provence, France, by Pierre Magnan

Lavotini, Sierra: exotic dancer and amateur sleuth in Panama City, Florida by Nancy Bartholomew

Lawless, Jane: lesbian restaurateur in Minneapolis, Minnesota by Ellen Hart

Belinda Lawrence: young Australian who inherited a cottage near Bath, England, by Brian Kavanagh

Lawson, Loretta: a  British feminist professor in London, England by Joan Smith

Lazar, Cally: a recovering lawyer and an alternative healer by Claire Daniels

Lazarus, Rina: wife of LAPD detective in Los Angeles, California by Faye Kellerman

Lazenby, Ben: British Council official in England by James Melville

Leaphorn, Lieutenant Joe: Navajo tribal police officer in the Southwest by Tony Hillerman

Le Brun, John: a retired sheriff in 1890s in  Brunswick, Georgia by Brent Monahan

Lecter, Hannibal: a serial killer in North America by Thomas Harris

Leduc, Aimee: an owner of a detective agency specializing in corporate security, in Paris, France by Cara Black

Lee, Anna: private investigator in London, England by Liza Cody

Lee, Heaven: trendy restaurant owner-chef in Kansas City, Missouri by Lou Jane Temple

Lee, Will: the chief aide to a senator in Georgia by Stuart Woods

Lee, Quong: an elderly Chinatown philosopher in London, England by Thomas Burke

Leidl, Constance: psychologist in New York by Kate Wilhelm

Samantha Leiffer: preschool teacher in New York City, by Alison Gaylin

Sir Edward Leithen: lawyer in Scotland and Canada, by John Buchan

Chief Inspector Lennox: detective chief inspector in Yorkshire, England, by John Wainwright

Lennox, Dorie: a new private investigator in Kansas City, Missouri by Lise McClendon

Lennox, Tory: Lieutenant - U.S. Coast Guard in Santa Barbara, California by Tony Gibbs

Tim LePage: detective inspector, and Anna Weston, a veterinarian, on the island of Guernsey, UK, by Eileen Dewhurst

Leric, a detective inspector for Scotland Yard in London, England by Roger Busby

Lestrade, Sholto Joseph: Scotland Yard inspector in 19th century London, England by M.J. Trow

LeVendeur, Catherine: novice and scholar in 12th century France by Sharan Newman

Roger Levin: 1970s marijuana dealer and shrewd operator who does for others what they would prefer not to do themselves, by Alan Furst

Rebecca Levis: medical student, later MD, and Ben Candidi, a free-spirited, nature-loving biomedical scientist, in Florida, Washington, DC, and elsewhere, by Dirk Wyle

Levy, Rebecca: a figure skating researcher by Alina Adams

Lewis, Wyn: a real estate attorney Long Island, New York by David A. Kaufelt

Lewis, Janine: a single mother pregnant with her 4th child and the first woman Detective Chief Inspector in Greater Manchester, England by Cath Staincliffe

Liberty, Gilda: a small-town movie theater proprietor in Eden, Ohio by Della Borton

Libertus, mosaicist and an expert in puzzles and patterns, living in the ancient Roman town of Glevum (now Gloucester), England by Rosemary Rowe

Lieberman, Abe: 60-something Jewish police detective in Chicago, Illinois by Stuart Kaminsky

Max Liebermann: psychoanalytic detective in turn-of-the-20th-century Vienna, Austria, by Frank Tallis

Liffey, Jack: a private investigator in Los Angeles, California by John Shannon

Light, Robin: pet store owner in Syracuse, New York by Barbara Block

Lightfoot, Marie: true crime author by Nancy Pickard

Lightstone, Harry: U. S. Fish & Wildlife Department in the U.S.A. by Ken Goddard

Aramus P. Limpkin: professor of history at a college in Georgia, and Dr. Galimatias, a semi-retired physician based in New Orleans, Louisiana, by H.O. Ward

Ann Lindell and Ola Haver, detectives in the Violent Crime Division, in Uppsala, Sweden, by Kjell Eriksson

Sarah Lindstrom: police detective, and Meg Darcy, a working-class lesbian private investigator, in St. Louis, Missouri, by Jean Marcy

Linnet, Birdie: ex-cop fitness trainer in London, England by Gillian Linscott

Lindsey, Hobart: an insurance claims adjuster for valuable collectibles in California by Richard A. Lupoff

Nicholas Linnear: half-Asian, half-English crime fighter, by Eric Van Lustbader

Linton, Sara: a pediatrician and coroner in Grant County, Georgia by Karin Slaughter

Cassandra Lisle: college student in late-1960s Chicago, Illinois, in the Cook County mysteries by Charlotte Carter

Lisle, Darina: a caterer-chef and food writer in West Country, England by Janet Laurence

May List: senior sleuth, on her own after 35 years of marriage, in Washington, by T. Dawn Richard

Thomas Littlejohn: police inspector, later Superintendent, mostly in England, by George Bellairs

LLewellyn, DS Dafyd and DCI Joseph Rafferty are assigned to the police station in Elmhurst in Essex, England by Geraldine Evans

Thomas Llewelyn: ex-student and ex-thief, now assistant to Cyrus Barker, a private detective, in Victorian London, England, by Will Thomas

Llorca, Juan: a sergeant in the Civil Guard in Spain by Delano Ames

Lloyd, Chief Inspector: a cop in East Anglia, England by Jill McGown

Lloyd, DS Gomer: a policeman in Cardiff, Wales by David Williams

Lloyd, Hilary: police sergeant in East Anglia, England by Sheila Radley

Locke, Jeremy: an attorney in England by Mary Challis

John Locke: ex-SAS counterterrorist operative, now a globetrotting bodyguard, based in Canada by Jack Barnao (Ted Wood)

Logan, Whitney: a 20-something attorney in Los Angeles, California by Mercedes Lambert

Lombardi, Susan: a professor at a university in Connecticut by Carole B. Shmurak

Lomax, Jacob: an ex-cop turned private investigator in Denver, Colorado by Michael Allegretto

Mike Lomax and Terry Biggs, police detectives in Los Angeles, California, by Marshall Karp

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

Lombardo, Joe and Barry Gilbert, police homicide detectives in Toronto, Ontario, Canada by Scott Mackay

London, Jack: the author in 1890s (before his famous novels) in San Francisco, California by Peter King

Longchamp, Faye: a black archaeology student digging up artifacts for the black market on her plantation on North Florida’s Gulf Coast by Mary Anna Evans

Lonto, Tony: police detective in the United States by E. Richard Johnson

Lord, Emma: small-town newspaper owner and editor in Alpine, Washington by Mary Daheim

Squabbling lawyers Steve Solomon, a Coconut Beach bum and Victoria Lord, a Miami blue blood, in Florida by Paul Levine

DCI Lorimer and Dr. Soloman Brightman, a psychologist and criminal profiler, in Glasgow, Scotland, by Alex Gray

Graham Lorimer: investigator for the Home Office concerning infringements on British interests overseas, by Ian Stuart

Darcy Lott: movie stuntwoman and Zen practitioner, in northern California, by Susan Dunlap

BeBe Loudermilk: a triple-divorced restaurant owner, and Eloise “Weezie” Foley, recently divorced antique dealer, in Savannah, Georgia, by Mary Kay Andrews (Kathy Hogan Trocheck)

Loudermilk, Dottie: one-half of a black retired couple traveling in the USA  by Gar Anthony Haywood

Loudermilk, Joe: one-half of a black retired couple traveling in the USA  by Gar Anthony Haywood

Love, Pharoah: a gay, black NYPD detective in New York, New York by George Baxt

Lovejoy: antiques expert and forger in East Anglia, England by Jonathan Gash

Lovelace, Clarisse: a straight half-owner of a gay bar in Boston, Massachusetts by Nathan Aldyne

Ambrose Low: ex-criminal, and Colonel Brain, an ex-army officer, in England, by Henry Cecil

Philipa Lowe: amateur sleuth, and Oliver Simpson, a Detective Inspector, in England, by Roger Omerod

Lowry, Gideon: a 50-something, piano-playing private detective in Key West, Florida by John Leslie 

Ed Loy: Irish private investigator who has been living in Los Angeles, returning home to Dublin, Ireland, by Declan Hughes

Lubbock, John Spencer: a retired World War II DCI, in Great Britain by Brian Cooper

Luce, Zoe: a psychic interior decorator in Whispering Springs, Arizona by Jayne Ann Krentz

Lucci, Victoria: a risk manager at a Denver hospital in Denver, Colorado by Suzanne Proulx

Lucio, Ramon, Milos, and Neil meet for lunch and take turns to tell their stories, in the Lunch series by Derek Hansen

LuEllen: thief in Minneapolis, Minnesota by John Sandford

Lukas, Margaret: FBI Special Agent by Jeffery Deaver

Nora Lumley: public defender in Marion County, Indiana, by D.R. Schanker

The Lunghi family: a 3-generation private eye family in Bath, England by Michael Z. Lewin

Lupa, Auguste: British Secret Service agent with U.S. passport by John Lescroart

Inspector Lyle: detective inspector in Yorkshire, England, by John Wainwright

Colin Lynch: international espionage agent, by Paul Mann

Lynch, Jack: public relations man and problem solver in New Orleans, Louisiana by Steven Womack

Lynley, Thomas: Scotland Yard inspector in London, England by Elizabeth George

Lynx, Jason: antiques dealer and interior decorator in Denver, Colorado by A. J. Orde

Brad Lyon: retired San Francisco homicide inspector, and his wife Ashleigh, teddy bear collectors in the Shenandoah Valley of Virginia, in the Bear Collector’s mysteries by John J. Lamb