Pedro Avilés Pérez (April 11, 1931 – September 15, 1978), also known as "El León de la Sierra" (English: "The Mountain Lion"), was a Mexican drug lord in the state of Sinaloa beginning in the late 1960s.

Vladimir Viktorovich Storozhenko (Russian: Влади́мир Ви́кторович Стороже́нко; 11 April 1953 – 22 September 1982), known as The Smolensk Strangler (Russian: Смоленский душитель), was a Soviet serial killer.

Miklós Horthy de Nagybánya (18 June 1868 – 9 February 1957) was a Hungarian admiral and statesman who was the regent of the Kingdom of Hungary during the interwar period and most of World War II, from 1 March 1920 to 15 October 1944.

Henri Désiré Landru (12 April 1869 – 25 February 1922) (French pronunciation: [ɑ̃ʁi deziʁe lɑ̃dʁy]) was a French serial killer, nicknamed the Bluebeard of Gambais and a prolific marriage fraudster. He is confirmed to have murdered at least ten women and the teenage son of his first victim, primarily targeting lonely war widows whom he met through newspaper advertisements, seduced, defrauded of their assets, and then killed, disposing of their bodies by burning them in his stove.

Denis Sergeevich Pischikov (Russian: Дени́с Серге́евич Пи́счиков; born 12 April 1983), known as The Shivering Creature (Russian: Тварь дрожащая), is a Russian robber and serial killer, who killed 14 elderly people between 2002 and 2003 in the Moscow Oblast and Vladimir Oblast.

Antonio López y López, 1st Marquess of Comillas, GE (1817 in Comillas – 1883 in Barcelona), was a Spanish businessman, slave trader and shipping magnate. He was the founder of several important companies and one of the world's wealthiest individuals in the second half of the nineteenth century.

Enedina Arellano Félix de Toledo (born April 12, 1961) is a Mexican drug lord who, alongside her brothers, founded the Tijuana Cartel and played a role as a logistical accountant for the criminal organization.

Julio César Arana del Águila, (April 12, 1864 – September 7, 1952) was a Peruvian entrepreneur and politician.

Ion Antonescu (; Romanian: [iˈon antoˈnesku] ; 14 June [O.S. 2 June] 1882 – 1 June 1946) was a Romanian military officer and marshal who presided over two successive wartime dictatorships as Prime Minister and Conducător during most of World War II.

Roman Vladimirovich Burtsev (Russian: Рома́н Влади́мирович Бу́рцев; 13 April 1971 – December 2023), known as The Chikatilo of Kamensk (Russian: Каменский Чикатило), was a Russian serial killer and child sex offender. Between 1993 and 1996, he raped and strangled six young children: five girls and one of the victims' brother.

Vidkun Abraham Lauritz Jonssøn Quisling (; Norwegian: [ˈʋɪ̂dkʉn ˈkʋɪ̂slɪŋ] ; 18 July 1887 – 24 October 1945) was a Norwegian military officer, politician and Nazi collaborator who headed the government of Norway during the country's occupation by Nazi Germany during World War II.

Leonarda Cianciulli (14 April 1894 – 15 October 1970) was an Italian serial killer. Better known as the Soap-Maker of Correggio (Italian: la Saponificatrice di Correggio), she murdered three women in the town of Correggio, Reggio Emilia, in 1939 and 1940, and turned their bodies into soap (using caustic soda) and teacakes.

Bruce Delane Mendenhall (born April 14, 1951) is a convicted American serial killer. He was arrested in Tennessee in July 2007 and found guilty in 2010 of the June 26, 2007 murder of Sara Hulbert.

Paul Charles Denyer (born 14 April 1972, known briefly as Paula whilst in prison) is an Australian serial killer currently serving three consecutive sentences of life imprisonment with a non-parole period of 30 years for the murders of three young women in Melbourne, in 1993. Denyer became known in the media as the Frankston Serial Killer as his crimes occurred in the neighbouring suburbs of Frankston.

François Duvalier (14 April 1907 – 21 April 1971), also known as Papa Doc, was a Haitian politician and physician who served as president of Haiti from 1957 until his death in 1971.

Brydon Brandt (born 15 April 1964) is a South African serial killer who murdered at least four people in the Eastern Cape between 1989 and 1997. He first murdered two prostitutes after picking them up from bars in Port Elizabeth, then a female roommate in 1996.

Donald Harvey (April 15, 1952 – March 30, 2017) was an American serial killer who claimed to have murdered 87 people, though he has 37 confirmed victims. He was able to do this during his time as a hospital orderly.

Michelle Knotek is an American convicted murderer from Raymond, Washington. She was convicted in 2004 of second degree murder and first degree manslaughter for her role in the torture and deaths of Kathy Loreno and Ronald Woodworth, who were both boarders in Knotek's home.

Kim Il Sung (born Kim Song Ju; 15 April 1912 – 8 July 1994) was a North Korean revolutionary, military commander, politician, and dictator who founded the Democratic People's Republic of Korea (DPRK), also known as North Korea, in 1948, and led the country from its establishment until his death in 1994. He was succeeded by his son Kim Jong Il and was declared Eternal President.

Zheng Zhilong (Chinese: 鄭芝龍; pinyin: Zhèng Zhīlóng; Wade–Giles: Ching Chih-lung; Pe̍h-ōe-jī: Tēⁿ Chi-liông; April 16, 1604 – November 24, 1661), baptismal name Nicholas Iquan Gaspard, was a Chinese admiral, merchant, translator, military general, politician, and pirate leader of the late Ming dynasty who later defected to the Qing dynasty. He was the founder of the Zheng clan and the father of Zheng Chenggong (Koxinga), who would later establish the pro-Ming Kingdom of Tungning in Taiwan, thus making him an ancestor of the House of Koxinga.

Wan Kuok-koi (Chinese: 尹國駒; born 1955), popularly known as Broken Tooth Koi (崩牙駒), is a "businessman" and former leader of the Macau branch of the 14K triad, considered Chinese mafia. He was released after about 14 years in prison in December 2012.

Hiroaki Hidaka (日高 広明, Hidaka Hiroaki; 17 April 1962 – 25 December 2006) was a Japanese serial killer.

Željko Ražnatović (Serbian Cyrillic: Жељко Ражнатовић, pronounced [ʒêːʎko raʒnâːtoʋitɕ]; 17 April 1952 – 15 January 2000), better known as Arkan (Serbian Cyrillic: Аркан), was a Serbian warlord, mobster and head of the Serb paramilitary force called the Serb Volunteer Guard during the Yugoslav Wars, considered one of the most feared and effective paramilitary forces during the wars. His paramilitary unit was responsible for numerous crimes in Eastern Bosnia, including murder, pillaging, rape and ethnic cleansings.

Allan Ronald Ross (17 April 1944 – 21 August 2018), better known as "Allan the Weasel", was a Canadian gangster best known for leading the West End Gang of Montreal. At the time of his arrest in Florida in 1991, he was described by American law enforcement as the fifth most important drug kingpin in the world.

Sirhan Bishara Sirhan (; Arabic: سرحان بشارة سرحان Sirḥān Bišāra Sirḥān; born March 19, 1944) is a Palestinian-Jordanian man who assassinated U.S. senator Robert F.

Yoo Young-chul (Korean: 유영철; born 18 April 1970), also known as the Raincoat Killer or Raincoat Man, is a South Korean serial killer, sex offender, and self-confessed cannibal. After he admitted to the murders of multiple people, mostly prostitutes and wealthy old couples, the Seoul Central District Court convicted him of 20 murders, although one case was dismissed when it turned out that the crime had been committed by another serial killer, Jeong Nam-gyu.

Herbert William Mullin (April 18, 1947 – August 18, 2022) was an American serial killer who killed 13 people in California in the early 1970s. He confessed to the killings, which he claimed prevented earthquakes.

Martha Wise (née Hasel; April 18, 1883 – June 28, 1971) was an American poisoner and serial killer. After her husband died and her family forced her to end a relationship with a new lover, Wise retaliated by poisoning seventeen family members, of whom three died, in 1924.

Jacob Luitjens (18 April 1919 – 14 December 2022) was a Dutch collaborator during World War II. He was nicknamed the terror of Roden, as he was active in and around Roden in the Drenthe Province.

Lucrezia Borgia (18 April 1480 – 24 June 1519) was an Italian noblewoman of the House of Borgia who was the illegitimate daughter of Pope Alexander VI and Vannozza dei Cattanei. She was a former governor of Spoleto.

Dzhokhar Anzorovich Tsarnaev (born July 22, 1993) is an American domestic terrorist and mass murderer of Chechen and Avar descent. Along with his older brother Tamerlan Tsarnaev, he planted pressure cooker bombs near the finish line of the Boston Marathon on April 15, 2013.

Anatoly Petrovich Sedykh (Russian: Анато́лий Петро́вич Седы́х; 20 April 1963 – 11 June 2023) was a Russian serial killer.

Adolf Hitler (20 April 1889 – 30 April 1945) was an Austrian-born German politician who was the dictator of Germany during the Nazi era from 1933 until his suicide in 1945. He rose to power as the leader of the Nazi Party, becoming the chancellor of Germany in 1933 and then taking the title of Führer und Reichskanzler in 1934.

Martin Dumollard (June 22, 1810 − March 8, 1862) was a French serial killer condemned to the guillotine after having been arrested and charged with the deaths of maids from 1855 to 1861. His victims were approached in Lyon by Dumollard, who offered them a nice house in Côtière.

Robert Black (21 April 1947 – 12 January 2016) was a Scottish serial killer and paedophile who was convicted of the kidnap, rape and murder of four girls aged between 5 and 11 in a series of crimes committed between 1981 and 1986 in the United Kingdom.

Donald Lehman (1933 – January 8, 1981) was an American man who was murdered in front of his family by four men in Arkansas. All four men – James William Holmes, Hoyt Franklin Clines, Michael Orndorff, and Darryl Richley – were convicted of capital murder and sentenced to death, albeit Orndorff's sentence was reduced to life without parole on appeal.

Staf Van Eyken (Dutch pronunciation: [ˈstɑfɑn ˈɛikə(n)]; born 21 April 1951) is a Belgian serial killer who strangled three women between October 1971 and March 1972 in Mechelen and Bonheiden. Because he liked to bite his victims, he got the nickname The Vampire of Muizen.

Gerolamo "Nino" Bixio (Italian: [dʒeˈrɔːlamo ˈniːno ˈbiksjo], Ligurian: [ˈniːnu ˈbiːʒu]; 2 October 1821 – 16 December 1873) was an Italian general, patriot and politician, one of the most prominent figures in the Italian unification.

Thomas W. Piper (April 22, 1849 – May 26, 1876), known as The Boston Belfry Murderer, was a Canadian-born American murderer who murdered two underage girls between 1873 and 1875 in Massachusetts and confessed to having done such to one other.

Luigi Lucheni (born Louis Lucheni; 22 April 1873 – 19 October 1910) was an Italian anarchist and the assassin of Empress Elisabeth of Austria.

Antonio Nirta (22 April 1919 – 1 September 2015) was a boss of the 'Ndrangheta, a Mafia-type organization, in the Italian region of Calabria. Together with his brothers Giuseppe, Francesco, and Sebastiano, he ruled San Luca, a stronghold of the 'Ndrangheta.

Domingo de Acassuso (1658–1727) was a Spanish politician and military man, who served as mayor of Buenos Aires in 1716. He was the founder of the city of San Isidro in Buenos Aires Province.

Vladimir Anatolyevich Mukhankin (Russian: Владимир Анатольевич Муханкин, born 22 April 1960) is a Russian serial killer, convicted for the murder of 9 people in Rostov Oblast in 1995.

Henri Lafont (born Henri Chamberlin, 22 April 1902 – 26 December 1944) was an underworld figure who headed the Carlingue, French auxiliaries for the German security services, during the German occupation of France in World War II.

Nikolay Alexandrovich Sakharov (Russian: Никола́й Алекса́ндрович Са́харов; 22 April 1954 – 5 February 1979), known as The Vologda Ripper (Russian: Вологодский потрошитель), was a Soviet serial killer, who became a figurant of one of the most high-profile trials in Vologda.

Adam Peter Lanza (April 22, 1992 – December 14, 2012) was an American mass murderer responsible for the Sandy Hook Elementary School shooting, one of the deadliest mass shootings in the US. On December 14, 2012, he fatally shot his mother, Nancy Lanza, at their home in Newtown, Connecticut, before driving to Sandy Hook Elementary School, where he killed 20 children between the ages of six and seven, and six adult staff members.

Vladimir Ilyich Ulyanov (22 April [O.S. 10 April] 1870 – 21 January 1924), better known as Vladimir Lenin, was a Russian revolutionary, politician and political theorist.

Dagmar Johanne Amalie Overbye (Danish: [ˈtɑwmɑ ˈɒwɐˌpyˀ]; 23 April 1887 – 6 May 1929) was a Danish serial killer. She murdered between nine and 25 children, including one of her own, during a seven-year period from 1913 to 1920.

Edward James Adams (April 23, 1887 – November 22, 1921) was a notorious American criminal and spree killer in the Midwest. He murdered seven people—including three policemen—over a period of around 14 months and wounded at least a dozen others.

Armin Meiwes (German: [ˈmaɪvəs]; born 1 December 1961) is a German former computer repair technician who received international attention for murdering and cannibalising Bernd Brandes, whom he had found via the Internet as a voluntary victim, in March 2001.