Please be aware this is a hobby so will only be done as and when I have the time.
In country of origin order
* Akira Nishiguchi
* Kiyoshi Okubo:
* Nikolai Dzhumagaliev: AKA "Metal Fang"
* Kaspars Petrovs:
* Vlado Taneski:
* Juana Barraza: AKA "Mataviejitas" ("Old Lady Killer");
* José Luis Calva: cannibal;
* Adolfo Constanzo: AKA "The Godfather of Matamoros"
* Delfina and María de Jesús González: AKA "Las Poquianchis";
* Raúl Osiel Marroquín: AKA "El Gato Imperial"
* Maria Swanenburg
* Minnie Dean:
* Arnfinn Nesset:
* Javed Iqbal:
Poland
* Zdzislaw Marchwicki: AKA "Zaglebie Vampire"; convicted of murdering 14 women; executed in 1976
* Wladyslaw Mazurkiewicz: AKA "The Gentleman Killer"; killed up to 30 women
* Stanislaw Modzelewski: murdered seven women in Lódz during the 1960s; executed in 1970
* Leszek Pekalski: AKA the "Vampire of Bytów"; killed up to 17 women
* The Skin Hunters (Andrzej Nowocien, Karol Banas, Dr. Janusz Kulinski, Dr. Pawel W.): four medics in Lódz who killed patients for profit
Portugal
* António Luís Costa: ex-GNR officer who murdered three women between 2005 and 2006.
Romania
* Vera Renczi: poisoned two husbands, one son and 32 of her suitors in the 1920s and 1930s
* Ion Rîmaru: murdered and raped young women in Bucharest from 1970 to 1971; executed in 1971
Russia
* Valeriy Asratyan: arrested in 1990 and convicted of three murders and dozens of cases of sexual abuse; executed
* Andrei Chikatilo: AKA "The Rostov Ripper"; killed 52 women and children throughout the Soviet Union; arrested, convicted and executed in 1994
* Sergey Golovkin: AKA "The Fisher" killed 11 boys between 1986 and 1992
* Vasiliy Kulik: killed 13 people aged between seven months and 75 years; executed
* Maxim Petrov: AKA "Doctor Killer" and "Doctor Death"; doctor who killed 12 patients
* Alexander Pichushkin: AKA "The Chessboard Killer"; convicted of 48 murders; confessed to killing 63
* Sergei Ryakhovsky: AKA "The Hippopotamus"; convicted of the murders of 19 people aged between 14 and 78
* Darya Saltykova: 18th century countess who tortured and killed serfs on her estate
* Anatoly Slivko: convicted of killing seven young boys; executed
* Alexander Spesivtsev: cannibal convicted of the murders of 19 women
Slovenia
* Silvo Plut: killed three women; committed suicide in prison in 2007
* Metod Trobec: raped and killed at least five women; committed suicide in prison in 2006
South Africa
* Sibusiso Duma: murdered 7 people in the Pietermaritzburg area of KwaZulu Natal in 2007.
* Cedric Maake: AKA the "Wemmer Pan Killer"; serial rapist; murdered at least 27 people from 1996 - 1997.
* Jimmy Maketta: AKA "Jesus Killer" convicted on 16 counts of murder, 19 counts of rape from 1996 - 1999.
* Johannes Mashiane: AKA "The Beast of Atteridgeville" 13 counts of murder, 12 counts of sodomy from 1982 - 1989.
* Daisy de Melker: poisoner; killed two husbands and one son from 1923 - 1932.
* Elifasi Msomi: AKA "The Axe Killer" murdered 15 people under the influence of the Tokoloshe from 1953 - 1955.
* Nicholas Lungisa Ncama: murdered 6 people in the Eastern Cape, 1997.
* David Randitsheni: AKA "Modimolle Serial Killer" raped and murdered 10 children (kidnapped and raped more) from 2004 - 2008.
* Samuel Sidyno: AKA "Capital Hill Serial Killer" murdered 7 people in Pretoria from 1998 - 1999.
* Norman Afzal Simons: AKA "Station Strangler" raped, sodomised and murder 22 children on the Cape Flats from 1986 - 1994.
* Moses Sithole: AKA "ABC Killer" raped and killed at least 38 young women in Atteridgeville, Boksburg and Cleveland from 1994 - 1995.
* Sipho Thwala: AKA the "Phoenix Strangler"; raped and murdered 19 women in the sugarcane fields of KwaZulu Natal from 1996 to 1997.
* Gert van Rooyen: allegedly abducted and murdered at least six girls from across South Africa from 1988 - 1989.
* Stewart Wilken: AKA "Boetie Boer"; raped, sodomised and murdered at least 7 victims from 1990 - 1997.
* Elias Xitavhudzi: AKA "Pangaman" murdered 16 people in Atteridgeville in the 1960s.
* Christopher Mhlengwa Zikode: AKA "Donnybrook Serial Killer" murdered 18 people in Donnybrook KwaZulu Natal from 1994–1995.
South Korea
* Yoo Young-chul: cannibal; killed 21 people from September 2003 to July 2004, mainly young women and rich men
Spain
* Francisca Ballesteros: between 1990 and 2004 killed her family and attempted to kill her surviving son
* Francisco Garcia Escalero: beggar convicted of 11 murders
* Enriqueta Martí: self-proclaimed witch who murdered and cannibalized six children in Barcelona; executed in 1912
* José Antonio Rodriguez Vega: raped and killed at least 16 women
* Manuel Delgado Villegas: 48 alleged murders; convicted of eight
Sweden
* Thomas Quick: AKA "Sätermannen"; confessed and convicted of eight murders, later recanted confessions
Turkey
* Adnan Çolak: AKA "Artvin Monster"; killed 17 elderly women in Artvan, Turkey from 1992 to 1995
* Özgür Dengiz: serial killer from Ankara, who killed four people and cannibalized at least one
Ukraine
* Anatoly Onoprienko: AKA "The Terminator"; murdered 59 people from 1989 until his capture in 1996
* Serhiy Tkach: convicted of raping and murdering 36 women, but claims the total is 100
* Nighttime Killers (Vladislav Volkovich and Vladimir Kondratenko): charged with shooting, stabbing and bludgeoning 16 victims to death in Kiev between 1991 and 1997; Kondratenko committed suicide in prison during the trial; Volkovich was found guilty and sentenced to life imprisonment
United Kingdom
* John Bodkin Adams: Was an Irish-born British general practitioner, convicted fraudster and suspected serial killer. Between the years 1946–1956, more than 160 of his patients died under suspicious circumstances
* Beverley Allitt: AKA "Angel of Death"; paediatric nurse who killed four babies in her care and injured at least nine others; sentenced to life imprisonment in 1991
* Robert Black: Scottish schoolgirl killer; convicted of three murders, suspected of many more
* Ian Brady and Myra Hindley: AKA "Moors Murderers"; murdered five children, aged between 10 and 17 and buried them in Saddleworth Moor
* Mary Ann Britland: poisoned her daughter, husband, and the wife of her lover in 1886
* William Burke and William Hare: notorious body snatchers in Edinburgh in the 19th century
* George Chapman: poisoned three women; suspected by some authors of being Jack the Ripper
* John Reginald Halliday Christie: killed at least six women (including his wife) between 1943 and 1953 and hid the bodies in his house. He has been implicated in the murders of one other woman and her infant child, of which Christie's fellow tenant, Timothy Evans, was convicted in 1950
* Robert George Clements: doctor who committed suicide when due to be arrested for poisoning his fourth wife. His other three wives all died suspiciously during the interwar period
* Mary Ann Cotton: British Victorian killer; said to have poisoned more than 20 victims; hanged in 1873
* Thomas Neill Cream: AKA "Lambeth Poisoner"; began his killing spree in the United States then moved to London; hanged in 1892
* Frederick Bailey Deeming: in 1891 killed his wife and four children in Britain; remarried and moved to Australia, and then murdered his new wife
* John Duffy and David Mulcahy: AKA the "Railway Killers"; killed three women near railway stations in the 1980s
* Amelia Dyer: murdered infants in her care; executed in 1896
* Kenneth Erskine: AKA "Stockwell Strangler"; sentenced to life imprisonment in 1988 for murdering seven pensioners
* Steven Grieveson: AKA "The Sunderland Strangler"; murdered three teenage boys in Sunderland, Tyne and Wear in 1993 and 1994
* John George Haigh: AKA the "Acid Bath Murderer" and the "Vampire of London"; active in England during the 1940s; convicted of six murders, but claimed to have killed nine; executed in 1949
* Archibald Hall: AKA the "Monster Butler"; killed five in the 1970s, three with accomplice Michael Kitto
* Anthony Hardy: AKA the "Camden Ripper"; convicted of three murders; suspected of at least four
* Trevor Hardy: AKA "The Beast in the Night"; killed three teenage girls in Manchester from 1974 to 1976
* Philip Herbert: AKA the "Infamous Earl of Pembroke"; 17th century nobleman convicted of manslaughter but discharged; later killed the prosecutor and pardoned for a third murder
* Colin Ireland: AKA "Gay Slayer"; killed five gay men in the early 1990s
* Michael Lupo: AKA "Wolf Man"; convicted of four murders and two attempted murders
* Patrick Mackay: charged with the murders of five individuals, convicted of three; confessed to killing 11 people
* Peter Manuel: Scottish murderer of seven, suspected of killing 15; executed in 1958
* Robert Maudsley: AKA "Hannibal The Cannibal"; killer of four; killed three in prison
* Peter Moore: businessman who killed four men at random in Wales
* Raymond Morris: AKA the "A34 Killer"; convicted of one murder, considered to have committed at least two more
* Robert Napper: AKA the "Green Chain Rapist"; killed two women and a child in the 1990s
* Donald Neilson: AKA "Black Panther"; killed four people, including heiress Lesley Whittle
* Dennis Nilsen: killer of 15 (possibly 16) men between 1978 and 1983
* Colin Norris: nurse convicted of killing four patients in Leeds hospitals
* William Palmer: AKA "Palmer the Poisoner"; doctor suspected of numerous murders, convicted of one; hanged on June 14, 1856
* Edward William Pritchard: Scottish doctor who poisoned his wife and her mother in 1865. Two years earlier their maid had died in a mysterious fire
* Amelia Sach and Annie Walters: murdered an unknown number of babies put up for adoption
* Harold Shipman: AKA "Dr.Death"; doctor convicted of 15 murders; a later inquiry stated he had killed at least 215 and possibly up to 457 people over a 25-year period
* George Joseph Smith: AKA "The Brides in the Bath"; killer of three women
* John Straffen: child killer and Britain's longest serving prisoner until his death on November 19, 2007
* Peter Sutcliffe: AKA the "Yorkshire Ripper"; convicted in 1981 of murdering 13 women and attacking seven more from 1975 to 1980
* Peter Tobin: killer of three women
* Thomas Griffiths Wainewright: artist considered to have poisoned four people
* Fred West and Rosemary West: AKA "House of Horrors"; she was convicted of 10 murders; both are believed to have tortured and murdered at least 12 young women between 1967 and 1987, many at the couple's home in Gloucester; he committed suicide in 1995 while awaiting trial
* Catherine Wilson: nurse considered to have poisoned seven people in the 19th century
* Mary Elizabeth Wilson: AKA the "Merry widow of Windy Nook"; convicted of murdering two husbands by poisoning and considered to have killed two others
* Steve Wright: AKA "The Suffolk Strangler" or "The Ipswich Ripper"; killed five women in six weeks around Ipswich in late 2006
* Graham Young: AKA "The Teacup Poisoner"; killed three people from 1962 to 1971
United States of America
* Charles Albright: AKA "The Eyeball Killer"; convicted of murdering three prostitutes in Dallas, Texas; sentenced to life imprisonment in 1991
* Rodney James Alcala: AKA "the Dating Game Killer"; convicted rapist and serial killer
* Amy Archer-Gilligan: poisoned a husband and four of her nursing home's residents with arsenic or strychnine in Windsor, Connecticut in the 1910s
* Joe Ball: AKA "The Alligator Man"; killed at least 20 women in the early 20th century in Texas
* Herb Baumeister: suspected of killing 20+ men along I-70; fled and committed suicide after remains of 11 were found on his Westfield, Indiana property
* Bloody Benders: family who killed guests at their inn in Labette County, Kansas in 1872
* Robert Berdella: convicted of killing six men in 1988 in Kansas City, Missouri; sexually tortured and dismembered his victims
* David Berkowitz: AKA "Son of Sam" and "The .44 Caliber Killer"; convicted of six murders in New York
* Kenneth Bianchi and Angelo Buono Jr: AKA the "Hillside Strangler"; killers of 13 women and possibly involved in three other killings
* Richard Biegenwald: convicted of killing five people in the early 1980s in the Asbury Park, New Jersey area; suspected in at least six other murders
* Arthur Gary Bishop: Utah man who murdered five young boys; executed in 1988
* Lawrence Bittaker and Roy Norris: kidnapped, tortured, raped and murdered five girls in 1979
* Terry Blair: Kansas City serial killer and rapist; active 1982–2004
* William Bonin: AKA "The Freeway Killer"; with several accomplices, claimed the lives of 20 boys in California
* Briley Brothers: three brothers and an accomplice responsible for 11 murders in the 1970s in Richmond, Virginia
* Jerry Brudos: AKA "The Lust Killer" and "Shoe Fetish Slayer"; killed at least five women in Oregon
* Ted Bundy: law student who raped and murdered more than 35 women in six states; executed in Florida State Prison on January 24, 1989
* Harvey Carignan: AKA the "Want-Ad Killer"; raped and beat four young women to death in 1972 and 1973 (convicted of two) having escaped hanging for a 1949 killing on a technicality
* David Carpenter: AKA the "Trailside Killer"; murdered five women on San Francisco-area hiking trails between 1979 and 1981
* Michael Bear Carson and Suzan Carson: nomadic hippie killers involved in the counter-culture movement; suspects in 12 homicides; sentenced to life imprisonment for three San Francisco Bay Area murders in 1983
* Dean Carter: murdered at least four women
* Richard Chase: AKA "The Vampire of Sacramento"; murdered six people in California the 1970s
* Doug Clark and Carol M. Bundy: AKA "Sunset Strip Killers"; killed at least seven people during 1980
* Carroll Cole: killed 16 people between 1948 and 1980; executed in 1985
* Alton Coleman and Debra Denise Brown: multi-state killers whose killings took place during two months in 1984; convicted of murder in three states
* John Norman Collins: committed in Ypsilanti and Ann Arbor between 1967 and 1969
* Ray Copeland and Faye Copeland: oldest couple ever sentenced to death in the United States at the ages of 75 and 69; convicted of killing five men; modus operandi was to hire unskilled drifters as farm hands and later kill them
* Dean Corll, Elmer Wayne Henley and David Brooks: committed the Houston Mass Murders in the 1970s
* Juan Corona: California killer convicted of murdering 25 men in 1971
* Richard Cottingham: AKA the "Torso Killer"; convicted of murdering five women in hotels around New York City between 1977 and 1980
* Andre Crawford a convicted serial killer, who killed 11 women between 1993 to 1997
* Charles Cullen: nurse in New Jersey and Pennsylvania who killed as many as 40 patients through lethal injection
* Jeffrey Dahmer: Milwaukee, Wisconsin cannibal who kept heads, skulls and body parts in his apartment for sexual gratification; convicted of 15 murders, but believed responsible for at least two others
* Albert DeSalvo: AKA "The Boston Strangler"; convicted of unrelated rapes; DeSalvo was never indicted for the Strangler murders, although he did confess to them
* Westley Allan Dodd: raped and murdered three boys in 1989; executed on January 5, 1993
* Ronald Dominique: confessed to raping and murdering at least 23 men in Louisiana; sentenced to eight life sentences in 2008
* Nannie Doss: AKA "The Giggling Granny" and "The Jolly Black Widow"; serial poisoner who killed 11 family members
* Paul Durousseau: murdered seven in southeast United States between 1997 and 2003; may have killed while stationed in Germany with the Army
* Mack Ray Edwards: convicted of murdering three children after confessing to the murders of six in Los Angeles County between 1953 and 1969; claimed at one point to have killed as many as 18
* Donald Leroy Evans: convicted of two stranglings and police closed the file on another; suspected of another dozen murders but recanted confessions to over 50 more
* Raymond Fernandez and Martha Beck: AKA the "Lonely Hearts Killers"; killed at least three women and one child in the 1940s but suspected in up to 20 murders in New York and Michigan
* Albert Fish: AKA the "Werewolf of Wisteria"; sadist and pedophile who cannibalized several children; convicted of one murder, confessed to 2 others,claimed to have molested 100 children
* Wayne Adam Ford: AKA "Wayward Wayne"; confessed to murdering four women; believed to have killed others
* Kendall Francois: serial killer from Poughkeepsie, New York who targeted prostitutes; after strangling the women, he would store them in various crawl spaces in and around his home
* Joseph Paul Franklin: racist serial killer who targeted interracial couples and attempted to assassinate Larry Flynt and Vernon Jordan; convicted of 11 murders and confessed to nine others
* John Wayne Gacy: AKA "Killer Clown"; killer of at least 33 men and boys; kept bodies buried under his Chicago home
* Gerald and Charlene Gallego: AKA the "Gallego Sex Slaves Killers"; kidnapped, raped and killed victims in the late 1970s; most of them were teenagers
* Carlton Gary: convicted of the murders of seven elderly women in Georgia
* Donald Henry "Peewee"" Gaskins: AKA "Meanest Man in America"; convicted of nine murders; confessed to more than 200; executed on September 6, 1991
* Ed Gein: two known victims, one suspected victim, four missing persons; elements of Gein's life and crimes have inspired, at least in part, the films Psycho and The Texas Chain Saw Massacre, and the novel/movie The Silence of the Lambs
* Janie Lou Gibbs: Georgia poisoner who killed five family members
* Kristen Gilbert: AKA the "Angel of Death"; nurse convicted of killing four by epinephrine injection
* Lorenzo Gilyard: killed up to 13 prostitutes in the Kansas City area 1977 to 1993
* Harvey Glatman: Californian rapist and killer of three women; lured women to pose for "bondage photographs"; executed September 18, 1959
* Billy Glaze: mission-oriented killer convicted of raping and murdering three Native American prostitutes in Minneapolis in 1986 and 1987
* Gwendolyn Graham and Cathy Wood: Michigan duo who murdered five elderly nursing home residents in their care and claimed to have killed another
* Dana Sue Gray: convicted of murder of three elderly women and attempted murder of a fourth in California
* Vaughn Greenwood: convicted of nine counts of murder, including eight of the "Skid Row Slasher" killings in southern California
* Belle Gunness: Norwegian-born murder-for-profit killer who killed her suitors and children in Indiana
* Anna Marie Hahn: German-born murder-for-profit killer who poisoned five elderly men; executed in 1938
* William Hance: AKA "The Forces Of Evil"; soldier who used the murders of Carlton Gary as an excuse for killing four women around military bases in 1977 and 1978
* Robert Hansen: Alaskan baker who killed prostitutes at his cabin; convicted of four murders but admitted to 11 others
* Donald Harvey: AKA "Angel of Death"; hospital orderly; confessed to more than 80 "mercy killings" with 37 confirmed killings
* Charles Ray Hatcher: convicted of two child murders in 1978 and 1982 having killed another in 1969; also stabbed to death a fellow inmate and another man 20 years apart
* Dale Hausner: Convicted of killing 8 people in random drive-by shootings in 2006 in Phoenix, Arizona
* William Heirens: AKA "The Lipstick Killer"; confessed to three murders spanning from June 1945 to January 1946
* Dr. H. H. Holmes: active from 1890 to 1894 during Chicago's 1893 World's Columbian Exposition; convicted of only one murder but definitively tied to at least eight more and confessed to a total of 27
* Waneta Hoyt: New York woman who murdered her five children
* Michael Hughes: killed four women in the Los Angeles area between 1992 and 1993; charged in 2008 with raping and murdering four additional women between 1986 and 1993
* Leslie Irvin: AKA "Mad Dog"; convicted of killing six people in Indiana in the mid-1950s; his Supreme Court case set a precedent for fair trials of highly publicized defendants
* Phillip Carl Jablonski: killed at least four women in California and Utah
* Keith Hunter Jesperson: Canadian serial killer convicted in the United States
* Vincent Johnson: AKA the "Brooklyn Strangler"; a homeless crack addict who killed at least five prostitutes
* Genene Jones: Texas pediatric nurse who poisoned infants in her care; convicted of only one murder but suspected of 10 or more others
* John Joubert: AKA the "Nebraska Boy Snatcher"; stabbed three children to death in 1982 and 1983
* Patrick Kearney: necrophiliac convicted of 21 murders in California and admitted to seven other murders
* Edmund Kemper: started killing when he was 15 years old in Santa Cruz, California; convicted of six murders and implicated in four others
* Tillie Klimek: Chicago woman who poisoned five husbands; sentenced to life imprisonment
* Paul John Knowles: raped and murdered 18 people
* Randy Kraft: convicted of the murders of 16 young men and boys; suspected of 51 others in California
* Timothy Krajcir: confessed to killing more than nine women—five in Missouri and four others in Illinois and Pennsylvania
* Peter Kudzinowski: killed children in New Jersey in the 1920s
* Leonard Lake and Charles Ng: ex-Marines and survivalists; killed at least 11 people and suspected of 25 in Wilseyville, California; collected and murdered female sex slaves
* Derrick Todd Lee: AKA the "Baton Rouge Serial Killer"; convicted of two murders; linked by DNA evidence to five others
* Henry Lee Lucas: convicted of 11 murders and confessed to approximately 3,000 others, although most of his confessions are considered outlandish; a task force set up to investigate his claims suggested that the true number of his murders may be as high as 213
* Bobbie Joe Long: AKA the "Classified Ad Rapist"; killed 10 women in Tampa Bay, Florida in 1984
* Rhonda Belle Martin: Alabama poisoner who murdered six family members; suspected of poisoning at least nine; executed in 1957
* Frederick Mors: Austrian who killed 17 elderly patients by poisoning in New York
* Herbert Mullin: schizophrenic in Santa Cruz, California who killed people to prevent earthquakes; convicted of 10 murders and confessed to three others
* Earle Nelson: AKA "Gorilla Man"; necrophiliac convicted and hanged for one murder; implicated in about 20 others
* Marie Noe: murdered eight of her children between 1949 and 1968
* Gordon Stewart Northcott: AKA the "Wineville Chicken Coop Murders"; California man who confessed to kidnapping, raping and murdering young boys with the aid of his mother, Sarah Louise Northcott in the 1920s; convicted of 3 murders, suspected of perhaps 20, executed in 1930
* Carl Panzram: murderer, rapist and arsonist; convicted of two murders; confessed to 19 others; executed in 1930
* Gerald Parker: AKA the "Bedroom Basher" raped and murdered five women and killed the unborn baby of a sixth woman in Orange County, California
* Christopher Peterson: AKA the "Shotgun Killer", confessed to shooting seven people with a shotgun in a killing spree spanning from October 30, 1990 to December 18, 1990 in Indiana.
* Dorothea Puente: convicted of three killings in Sacramento, California during the 1980s; suspected of six others
* Dennis Rader: AKA the "BTK Killer"; killed ten people between 1974 and 1991 in Sedgwick County, Kansas
* Richard Ramirez: AKA the "Night Stalker"; terrorized Los Angeles in 1984 and 1985; convicted of 14 murders
* David Parker Ray: convicted of rape and torture and sentenced to 224 years in prison; FBI believes he was responsible for the deaths of 60 women in Truth or Consequences, New Mexico
* Paul Dennis Reid: killed seven people during armed robberies between February and April 1997
* Ángel Maturino Reséndiz: killed nine people in Texas, Kentucky, and Illinois
* Gary Ridgway: AKA the "Green River Killer"; convicted of murdering 48 women in Washington state
* Joel Rifkin: murdered 17 women in the New York City and Long Island areas
* John Edward Robinson: AKA the "Cyber Sex Killer"; lured victims through the internet; convicted of murdering six women in Missouri and Kansas
* Dayton Leroy Rogers: murdered at least six women in Oregon
* Danny Rolling: pleaded guilty to murdering five students in Florida; executed in 2006
* Michael Bruce Ross: raped and murdered seven women in Connecticut; executed May 13, 2005
* Efren Saldivar: respiratory therapist who killed six patients, possibly as many as 120
* Altemio Sanchez: AKA the "Bike Path Rapist"; responsible for three murders and numerous rapes spanning a 25-year period in Buffalo, New York; currently serving three consecutive 75 years-to-life sentences for the murders
* Gerard John Schaefer: Florida police officer who killed up to 34 women and girls
* Charles Schmid: AKA the "Pied Piper of Tucson"; murdered three teenage girls in 1964 and 1965 and buried them in the desert
* Heriberto Seda: New York City copycat killer of the "Zodiac Killer" active from 1990 to 1994; convicted of shooting eight individuals, killing three; sentenced to life imprisonment in 1998
* Tommy Lynn Sells: convicted of only one murder; admitted to murdering dozens of people across the United States, possibly in excess of 70 although only six are confirmed
* Arthur Shawcross: AKA "The Genesee River Killer"; convicted of 12 murders; confessed to one more
* Robert Shulman: convicted of murdering five prostitutes between 1991 and 1996
* Lemuel Smith: confessed to the murders of five people, including an on-duty female prison guard
* Morris Solomon Jr.: handyman who killed six young women between 1986 and 1987 in Sacramento, California
* Timothy Spencer: AKA the "Southside Strangler"; raped and killed five women in Virginia between 1984 and 1987
* Gerald Stano: convicted murderer of 41 women; executed in 1998
* Cary Stayner: killed four women in Yosemite, California
* William Suff: AKA the "Riverside Killer"; killed up to 19 women near Riverside, California
* Michael Swango: physician and surgeon who poisoned over 30 of his patients and colleagues
* Marybeth Tinning: New York woman who smothered nine of her children to death
* Ottis Toole: Henry Lee Lucas' accomplice; convicted of six murders in Florida; confessed to but never tried for Adam Walsh's murder
* Jane Toppan: nurse and lust murderer who poisoned at least 31 patients and relatives in Massachussetts up to the turn of the 20th century
* Maury Travis: St. Louis area torture killer of 12–17 prostitutes from 2000 to 2002
* Chester Turner: murderer of women in Los Angeles, California; convicted of 12 murders and linked through DNA evidence to another
* Henry Louis Wallace: Charlotte, North Carolina killer of at least nine young women from 1992 to 1994
* Carl Eugene Watts: convicted of two murders; admitted to killing 80 people in Texas and Michigan; possibly guilty of 100 murders
* Nathaniel White: convicted of stabbing to death six women in the Hudson Valley, New York area from 1991 to 1992
* Wayne Williams: convicted of two murders; police claim his arrest solved 23 in the string of 28 Atlanta Child Murders
* Randall Woodfield: AKA the "The I-5 Killer" and "The I-5 Bandit"; convicted of four murders; believed responsible for 14 others
* Aileen Wuornos: shot six men dead in Florida; executed in 2002
* Robert Lee Yates: murdered at least 13 women in Spokane County, Washington
Venezuela
* Dorangel Vargas: killed and cannibalized at least 10 men.