Radik Tagirovich Tagirov (Russian: Радик Тагирович Тагиров, Tatar: Радик Таһир улы Таһиров; born May 1982), dubbed the Volga Maniac, is a Russian serial killer who murdered 31 elderly women in and around the republic of Tatarstan between 2011 and 2012. In March 2024, he was sentenced to life in prison.

Max Gufler (1 May 1918 – 9 August 1966) was an Austrian serial killer who was convicted of killing four women. He was suspected of up to 18 murders.

Sergey Valerievich Lozovoi (Russian: Сергей Валерьевич Лозово́й; born May 1, 1965), known as The Giant (Russian: Великан), is a Russian criminal and serial killer who committed a series of brutal murders, for which he was wanted as a fugitive for a long time.

José Efraín Ríos Montt (Spanish: [efɾaˈin ˈrios ˈmont]; 16 June 1926 – 1 April 2018) was a Guatemalan military officer who served as de facto President of Guatemala from 1982 to 1983. His brief tenure as chief executive was one of the bloodiest periods in the long-running Guatemalan Civil War.

The Mahmudiyah rape and murders were a series of war crimes committed by four U.S. Army soldiers during the U.S.

Lester Joseph Gillis (December 6, 1908 – November 27, 1934), also known as George Nelson and Baby Face Nelson, was an American bank robber who became a criminal partner of John Dillinger when he helped Dillinger escape from prison in Crown Point, Indiana. Later, the Federal Bureau of Investigation (FBI) announced that Nelson and the remaining gang of bank robbers were collectively "Public Enemy Number One".

Jeffrey Don Lundgren (May 3, 1950 – October 24, 2006) was an American self-proclaimed prophet, cult leader, and mass murderer who, on April 17, 1989, killed a family of five in Kirtland, Ohio. Lundgren led a Latter Day Saint movement-based cult and interpreted scripture using an unconventional version of chiasmus, which involved searching a text for recurring patterns.

Emmett Dalton (May 3, 1871 – July 13, 1937) was an American outlaw, train robber and member of the Dalton Gang in the American Old West. Part of a gang that attempted to rob two banks in Coffeyville, Kansas, on October 5, 1892, he was the only member of five to survive, despite receiving 23 gunshot wounds.

Rubén Darío Millatureo Vargas (born May 3, 1962), known as The Jackal of Queilén (Spanish: El Chacal de Queilén), is a Chilean serial killer who murdered three people in the town of Queilén from 1997 to 1998.

Niccolò di Bernardo dei Machiavelli (3 May 1469 – 21 June 1527) was a Florentine diplomat, author, philosopher, and historian who lived during the Italian Renaissance. He is best known for his political treatise The Prince (Il Principe), written around 1513 but not published until 1532, five years after his death.

Renato Vallanzasca Costantini (Italian pronunciation: [reˈnaːto vallanˈdzaska, -ˈtsaska]; born 4 May 1950) is a notorious Italian mobster from Milan who was a powerful figure in the Milanese underworld during the 1970s.

Ryōichi Sasakawa (笹川 良一, Sasakawa Ryōichi; May 4, 1899 – July 18, 1995) was a Japanese businessman, far-right politician, class A war criminal, and philanthropist.

Muhammad Hosni El Sayed Mubarak (Arabic: محمد حسني السيد مبارك‎; 4 May 1928 – 25 February 2020) was an Egyptian politician and military officer who served as the 4th president of Egypt from 1981 until his resignation in 2011, following the Egyptian revolution. He was previously the 7th vice president under President Anwar Sadat from 1975 until his accession to the presidency, and the 41st prime minister from 1981 to 1982.

Leon Frank Czolgosz ( CHOL-gosh; Polish: [ˈlɛɔn ˈt͡ʂɔwɡɔʂ]; May 5, 1873 – October 29, 1901) was an American wireworker and anarchist who assassinated United States president William McKinley in 1901. Czolgosz had lost his job during the economic Panic of 1893 and turned to anarchism—a radical, anti-authoritarian political philosophy.

Luis Ignacio Vásquez Villenas (born 5 May 2002), better known by the nickname Lucho Plátano, is a Chilean criminal and serial killer currently imprisoned for four murders that occurred in the Santiago Metropolitan Region between May 2022 and January 2023, culminating with the murder of Daniel Valdés Donoso, commissioner of the Investigations Police of Chile (PDI). While he was a fugitive, he was declared by the courts as the “most wanted in Chile”.

Sophie Charlotte Elisabeth Ursinus (née Weingarten; 5 May 1760 – 4 April 1836) was a German serial killer believed to have been responsible for poisoning her husband, aunt, and lover, and of attempting to poison her servant. Her trial led to a method of identifying arsenic poisoning.

Joseph Potier (5 May 1768, Saint-Malo — 10 November 1830) was a French privateer and slave trader. He was one of the lieutenants of Robert Surcouf.

William Dale Archerd (May 5, 1912 – October 29, 1977) was an American serial killer who killed at least three people with insulin injections between 1956 and 1966 in Northern California. He was the first to be convicted of using insulin as a murder weapon in the US, and he is suspected in three more cases.

Zaven Sarkisovich Almazyan (5 May 1950 – 1973), known as the Voroshilovgrad Maniac (Russian: Ворошиловградский маньяк, romanized: Voroshilovgradskiy manyak), was a Soviet serial killer and rapist who committed a series of crimes in Rostov-on-Don and Voroshilovgrad between 1969 and 1970, including three murders.

John Wilkes Booth (May 10, 1838 – April 26, 1865) was an American stage actor who assassinated United States president Abraham Lincoln at Ford's Theatre in Washington, D.C., on April 14, 1865. A member of the prominent 19th-century Booth theatrical family from Maryland, he was a noted actor who was also a Confederate sympathizer; denouncing Lincoln, he lamented the then-recent abolition of slavery in the United States.

Sibusiso Derrick Duma (born 6 May 1984) is a South African serial killer who was convicted of two murders in 2007 and five murders in 2009 and sentenced to 8 life sentences in prison. He was mostly active around the City of Pietermaritzburg, KwaZulu Natal.

Raymond Martinez Fernandez (December 17, 1914 – March 8, 1951) and Martha Jule Beck (May 6, 1920 – March 8, 1951) were an American serial killer couple. They were convicted of one murder, are known to have committed two more, and were suspected of having killed up to twenty victims during a spree between 1947 and 1949.

Werner Boost (né Korecki; born 6 May 1928), nicknamed The Couples Killer, is a suspected German serial killer who allegedly committed double murders on couples in the 1950s. However, only one could be definitely proven - the murder of lawyer Bernd Servé in January 1953.

David Joseph Carpenter (born May 6, 1930), also called the Trailside Killer, is an American serial killer and sex offender who raped, tortured, and murdered various victims in the San Francisco Bay Area between 1979 and 1981. He was sentenced to death for seven murders and is believed to be responsible for several more.

Maximilien François Marie Isidore de Robespierre (; French: [maksimiljɛ̃ ʁɔbɛspjɛʁ]; 6 May 1758 – 28 July 1794) was a French lawyer and statesman, widely recognised as one of the most influential figures of the French Revolution. Robespierre fervently campaigned for the voting rights of all men and their unimpeded admission to the National Guard.

This is a list of mass stabbings that took place before 2010. It includes incidents in which there were at least three casualties (killed or injured).

Susan Denise Atkins (May 7, 1948 – September 24, 2009) was an American convicted murderer who was a member of Charles Manson's "Family". Manson's followers committed a series of nine murders at four locations in California over a period of five weeks in the summer of 1969.

Fernando Hernández Leyva (born 30 November 1964) is a Mexican serial killer. He was convicted in 1986 of 33 counts of murder committed in 5 different states of the Mexican union, but he confessed to killing around 100.

Dmitry Gennadyevich Kazakov (Russian: Дмитрий Геннадьевич Казаков; 7 May 1972 – 9 August 2022) was a Russian serial killer and robber who committed six robbery-murders in Novosibirsk and Tomsk Oblasts between 2009 and 2021.

Dale Devon Scheanette (May 7, 1973 – February 10, 2009), dubbed the Bathtub Killer, was an American serial rapist and murderer involved in two murders and several other rapes in Arlington, Texas. Scheanette first killed elementary school teacher Christine Vu by strangling her in her bathtub on September 17, 1996, and later murdered Wendie Prescott on December 24, 1996.

Marc Paul Alain Dutroux (French: [maʁk pɔl alɛ̃ dytʁu]; born 6 November 1956) is a Belgian convicted serial killer, serial rapist, and child molester. Initially convicted for the abduction and rape of five young girls in 1989, Dutroux was released on parole after just three years' imprisonment.

Danny Lee Barber (May 8, 1955 – February 11, 1999) was an American serial killer, necrophile, and burglar who murdered four people around Dallas County, Texas, between June 1978 and April 1980. He was convicted of three of the murders, sentenced to death for one of them, and executed by lethal injection in 1999.

Roberto D'Aubuisson Arrieta (dohb-wee-SOHN; 23 August 1943 – 20 February 1992) was a Salvadoran military officer, neo-fascist politician, and death squad leader. In 1981, he co-founded and became the first leader of the far-right Nationalist Republican Alliance (ARENA) and served as president of the Legislative Assembly from 1982 to 1983.

Carroll Edward "Eddie" Cole (May 9, 1938 – December 6, 1985) was an American serial killer who was executed in Nevada in 1985 for killing two women by strangulation. He was also convicted of murdering three other women in Texas and is believed to have murdered dozens between 1947 and 1980.

Greta Bösel (née Mueller) (9 May 1908 – 3 May 1947) was a Nazi German nurse and camp guard at Ravensbrück concentration camp. She was arrested and tried for her role in the Holocaust, found guilty of war crimes, and executed.

Charles Sobhraj (born Hotchand Bhawnani Gurmukh Sobhraj; 6 April 1944) is a French serial killer, fraudster, and thief whose victims were mainly Western tourists travelling on the hippie trail of South Asia during the 1970s. He is of Sindhi and Vietnamese origin.

The Dunblane massacre took place at Dunblane Primary School in Dunblane, near Stirling, Scotland, on 13 March 1996, when 43-year-old Thomas Hamilton killed 16 pupils and one teacher and injured 15 others before killing himself. It remains the deadliest mass shooting in British history.

Rédoine Faïd ([ʁe.dwan fa.id]; born 10 May 1972) is a French writer, and serial jailbreaker, considered France's most wanted criminal in 2013.

Robert William Pickton (October 24, 1949 – May 31, 2024), also known as the Pig Farmer Killer or the Butcher, was a Canadian pig farmer and serial killer. He is believed to have murdered at least 26 women, many of them sex workers from Vancouver's Downtown Eastside.

Mamadou Traoré (born May 11, 1973), known as The Bare-Handed Killer, is a Senegalese-born French serial rapist and murderer, responsible for assaulting at least six women, killing two of them, between April and October 1996.

Luis Felipe, also known as "King Blood", is a Cuban former gang leader and is the founder of the New York chapter of the Latin Kings (ALKN) street gang.

Kimberly LaGayle McCarthy (May 11, 1961 – June 26, 2013) was an American death row inmate and serial killer who was convicted and sentenced to death for the 1997 murder of her neighbor, 71-year-old retired college professor Dorothy Booth, in her Lancaster, Texas (Dallas–Fort Worth area) home during a robbery. Blood DNA evidence linked her to the murders of two other elderly Texas women, for which she was never tried.

Daniel Owen Conahan Jr. (born May 11, 1954) is an American convicted murderer, rapist, and suspected serial killer.

Sergey Anatolyevich Chyorny (Russian: Серге́й Анато́льевич Чёрный; 11 May 1977 – 24 June 2001), known as The Beast (Russian: Зверь), was a Ukrainian-born Russian serial killer who killed 10 girls aged between 15 and 23 years in Smolensk from August to December 1999.

Donald Arthur Piper (born May 11, 1961) is an American murderer and suspected serial killer convicted of killing two women in hotels around West Des Moines and Clive, Iowa in 1993 and 1997, but is considered a suspect in four other killings. For his confirmed crimes, Piper was convicted and sentenced to two life terms.

Harold Adrian Russell "Kim" Philby (1 January 1912 – 11 May 1988) was a British intelligence officer and a double agent for the Soviet Union. In 1963, he was revealed to be a member of the Cambridge Five, a spy ring that had divulged British secrets to the Soviets during World War II and in the early stages of the Cold War.

Ivan Roubal (12 May 1951 – 29 June 2015) was a Czechoslovak serial killer who was convicted of five murders.

Earle Leonard Nelson (né Ferral; May 12, 1897 – January 13, 1928), also known as the Gorilla Man, the Gorilla Killer, and the Dark Strangler, was an American serial killer, rapist, and necrophile who killed at least twenty women in various U.S. states and two in Canada between 1926 and 1927.

Michele Greco (Italian: [miˈkɛːle ˈɡrɛːko]; 12 May 1924 – 13 February 2008) was a member of the Sicilian Mafia and a convicted murderer. Greco died in prison while serving multiple life sentences.

Andrey Andreyevich Vlasov (Russian: Андре́й Андре́евич Вла́сов, September 14 [O.S. September 1] 1901 – August 1, 1946) was a Soviet Russian Red Army general.