L

• John M. Larn (1849–1877) - Both an outlaw and lawman in Shackleford County, Texas, Larn got involved in a tough vigilante group called the Tin Hat Brigade, who eventually killed him.

• James Franklin "Bud" Ledbetter (1852-1937) - Deputy Sheriff, Johnson County, Arkansas; U.S. Deputy Marshal, Oklahoma Territory; Sheriff, Muskogee County, Oklahoma.

• Isaiah W. Lees (1830–1902); Detective, San Francisco, California. Police Department.

• Ras Lewis - See Willard Erastus Christianson

• William Sidney "Cap" Light (1863?–1893) - Deputy sheriff, Belton, Texas, Temple, Texas and Creede, Colorado.

• Lighthorse Police (1844-1889) -  The Indian Police in Oklahoma were given the name Lighthorse by the Five Civilized Tribes when the state was still Indian Territory.

• Seldon T. Lindsey (1854-19??) - Lindsey worked as a cowboy and a buffalo hunter before becoming a U.S. Deputy Marshal in 1890.

• Steve Long, aka: Big Steve - A lawman and outlaw, Long ran the "Bucket of Blood" saloon in Laramie City, Wyoming and appointed himself assistant marshal. Long and his two partners were lynched on October 28, 1868.

• Harry Love (1809–1868) - Served as a Texas Ranger in the 1850s before moving to California and becoming Captain of the California Rangers in 1853. He allegedly brought in the head of Joaquin Murrieta, the Mexican outlaw.

M

• Christian "Chris" Madsen (1851–1944) A U.S. Deputy Marshal in Oklahoma Territory, Madsen worked closely with Heck Thomas and Bill Tilghman. Becoming known as the Three Guardsmen and were largely responsible for wiping out the lawlessness in Indian Territory.

• George Maledon, aka: Prince of Hangmen (1830-1911) - Maledon worked as a deputy sheriff in Fort Smith, Arkansas before he was appointed as a "special deputy" in charge of execution of the prisoners whom Judge Isaac Parker had condemned. For the next 22 years, he would execute more than sixty criminals, earning him the moniker of the "Prince of the Hangmen."

• Bryan Marsh (1833-1901) - After the Civil War, Marsh became a captain in the Texas Rangers in 1880. He later served as the Smith County, Texas sheriff.

• Edward J. Masterson, aka: Little Ed (1852–1878) - Brother of Bat Masterson and Dodge City, Kansas Marshal, killed in the line of duty by cowboys on April 9, 1878.

• James "Jim" P. Masterson (1855–1895) - Brother to Bat Masterson, James was a lawman in Dodge City and Ingalls, Kansas. He later served as a U.S. Deputy Marshal in Indian Territory. He fought the Doolin Gang and was part of the posse that forced Arkansas Tom Jones to surrender.

• Robert Masterson, aka: Smiling Bob - Another brother of Bat Masterson, Robert was marshal in Trinidad, Colorado in 1882. He reportedly killed twenty-one men.

• William Bartholomew "Bat" Masterson (1856?-1921) - Ford County Kansas Deputy Sheriff and Sheriff, Trinidad, Colorado Marshal, Dodge City Peace Commissioner, U.S. Deputy Marshal In New York. Later a reporter for a newspaper. Died of natural causes in 1921.

• Dave H. Mather, aka: Mysterious Dave (1851-1930?) - Known as both a lawman and an outlaw, Mather tended to lean towards the lawful side, serving as a Dodge City, Kansas Marshal; El Paso, Texas Assistant Marshal, and a U.S. Deputy Marshal in New Mexico. However, he was also involved with the lawless Dodge City Gang in Las Vegas, New Mexico and was suspected several times of horse and cattle rustling.

• Mike McCluskie, aka: Arthur Delaney, Art Donovan (18??-1871) - A little known gambler and occasional lawman, McCluskie instigated the Hide Park Gunfight on August 19th, 1871, in Newton, Kansas when he killed Billy Bailey a week earlier. When the smoke cleared he was severely wounded, shot by Hugh Anderson. He died six hours later.

• James McIntire (1846-1902) - A Texas gunman and lawman from 1860, he was a Texas Ranger, city marshal of Las Vegas, New Mexico, deputy sheriff, cowboy, hunter, gambler, and outlaw with a $1,000 reward on his head for the deaths of two men near Silver City, New Mexico.

• William Jesse McDonald (1852-1918) - Deputy sheriff in Mineola, Texas; U.S. Deputy Marshal in Indian Territory; captain in the Texas Rangers. Died of pneumonia in 1918.

• Joseph "Joe" W. McKidrict (1871-1894)  - Twenty-three year-old Texas Ranger, McKidrict was shot and killed by U.S. Deputy Marshal, Bass Outlaw on April 5, 1894 in El Paso, Texas.  When the U.S. Marshal created a disturbance at Tillie Howard's brothel and his gun accidentally went off, Constable John Selman and McKidrict quickly arrived. As the lawmen were trying to calm down the drunken Bass, he pointed his gun at McKidrict and shot him in the head and back, killing him instantly. Outlaw then fired at Selman, nearly striking him in the face and causing deep powder burns. Selman returned fire, hitting Outlaw just above the heart. As Bass staggered back he fired two more shots, hitting Selman above the right knee and in the thigh. Bass then staggered into the street where surrendered to Texas Ranger Frank McMahon. He died four hours later. McKidrict was buried in the Oakwood Cemetery in Austin, Texas.

• Thomas L. McKinney - A New Mexico gunman who was also a lawman, accompanied Pat Garrett to the shoot-out with Billy the Kid on July 14, 1881.

• Leander H. McNelly (1844–1877) - A Texas lawman, McNelly was commissioned as captain of the state police on July 1, 1870, and commanded the "Special Ranger Force" in 1874 which patrolled the Mexico border. He died on September 4, 1877.

• Mike Meagher (1844–1881) - Wichita, Kansas Marshal, U.S. Deputy Marshal in Indian Territory, and Caldwell, Kansas Mayor.

• Joseph Lafayette Meek (1810-1875) - After heading west from Virginia, Meek first spent his life as a mountain man before becoming a sheriff in the Willamette Valley of Oregon. Later won a seat in the legislature and appointed Oregon territory's first federal marshal.

• James B. Miller, aka: Killin' Jim, Killer Miller, Jim the Killer, Deacon Miller (1866-1909) - Killing his first man when he just 18, Miller became a hired gun in the 1880s, a "career" he would continue for the next two decades. He served as an occasional lawman in Pecos, Texas.  He killed Sheriff Bud Frazer and was suspected of forty other killings including Pat Garrett and AA. Bobbitt. On April 19, 1909, he was hanged by vigilantes in Ada, Oklahoma.

• Jeff Davis Milton (1861-1947) - A fearless lawman, Milton's career spanned more than half a century as he as police chief of EI Paso, Texas; a Texas Ranger, and a U.S. Deputy Marshal in New Mexico and Arizona.

• John "Happy Jack" Morco - A gunman and lawman in Ellsworth, Kansas. He he killed in a gunfight there with Policeman J. C. Brown.

• Joe Morgan - A gunman and lawman, he fought Deputy Sheriff Ben Williams in Las Cruces, New Mexico on September 15, 1895, with Albert Fall. He was later a deputy sheriff and Oliver Lee supporter.

• Harry N. Morse (1835–1912); Sheriff, Alameda County, California.

• Burton C. Mossman (1867–1956) - Managed the Hashknife Outfit of Arizona to try to stop the rampant cattle rustling before becoming the first captain of the Arizona Rangers in 1901.

N

• David Neagle (1847–1926) - Known as one of the fastest gunfighters in the west, Neagle served as Cochise County, Arizona Deputy Sheriff; Tombstone, Arizona Marshal; San Francisco, California Marshal and a U.S. Deputy Marshal.

• Thomas C. Nixon (1838?-1884) - Dodge City Assistant Marshal under Bill Tilghman, Nixon was shot and killed by "Mysterious" Dave Mather on July 21, 1824.

O

• Lon Oden - A Texas Ranger and gunfighter, Oden, along with Ranger John Hughes, participated in a number of gunfights along the Mexican border in the late 1800s.

• Robert “Bob” Ollinger (1841?-1881) – A crooked U.S. Marshal; Seven Rivers, New Mexico Marshal, and Lincoln County, New Mexico Deputy Sheriff, he was indicted for his participation in the Lincoln County War. He was shot and killed when Billy the Kid escaped from jail on April 28, 1881.

• William Owen O'Neill (1860-1898) - Yavapai County, Arizona Sheriff

• John C. Orrick - See George Washington Arrington

• Bass (Baz) L. Outlaw (18??-1894 ) - A lawman and Texas Ranger, Bass was dismissed in 1894 after shooting up the town of Alpine, Texas. Later he was appointed as a U.S. Deputy Marshal and was killed by John Selman on April 5, 1894.

• Commodore Perry Owens (1852–1919) - Apache County, Arizona Sheriff. He is credited with taming the lawless town of Holbrook, Arizona and during the Pleasant Valley War he was involved in the Owens-Blevins Shootout.

P

• Judge Isaac C. Parker (1838 - 1896) - Judge Isaac Parker often called the “Hanging Judge,” from Fort Smith, Arkansas ruled over the lawless land of Indian Territory in the late 1800s.

• George Peppin (1841-1904) - Served as Lincoln County Sheriff after the death of William Brady. A tool of the Dolan-Murphy faction of the Lincoln County War, Peppin led the raid on the McSween house on July 19, 1878 in Lincoln, New Mexico, which resulted in the deaths of several men. He was later indicted by a grand jury but all charges were dropped. Later, he worked as a butcher at Fort Stanton. He died in Lincoln County on 14th September, 1904.

• Lyon Phillipowski - A lawman and gunfighter who was involved in a shoot-out with a store clerk in Lincoln County, New Mexico on October 21, 1874.

• Tom Pickett (1858-1934) - An outlaw and lawman, Pickett stole cattle and was captured with outlaw Billy the Kid in New Mexico in December, 1880. Pickett also served as a Texas Ranger and U.S. Deputy Marshal. He died peacefully on May 14, 1934 in Arizona.

• The Pinkerton Detective Agency - Founded by Allan Pinkerton, a Scottish immigrant in 1850, the Pinkerton Agency quickly became one of the most important crime detection and law enforcement groups in the United States.

• Allan Pinkerton (1819–1884) - Founded the Pinkerton Detective Agency.

• William A. Pinkerton (1846–1923) - The son of Allan Pinkerton, William served as a Pinkerton Detective.

• Robert Pinkerton (1848–1907) - The son of Allan Pinkerton, Robert served as a Pinkerton Detective.

• Henry Plummer (1837–1864) - Nevada City, California Marshal and Bannack, Montana Sheriff. Was accused of leading a ruthless gang called the Innocents and was hanged by vigilantes, just as he was about to become U.S. Deputy Marshal of the Territory.

• Robert Jack Price (1848–1930) - Constable for Potawatomie County, Oklahoma and later a U.S. Deputy Marshal.

Q