John Demjanjuk (born Ivan Mykolaiovych Demjanjuk 3 April 1920 – 17 March 2012), was a Trawniki and Nazi camp guard at Sobibor extermination camp, Majdanek, and Flossenbürg. Demjanjuk became the center of global media attention in the 1980s, when he was tried and convicted in Israel after being identified as "Ivan the Terrible", a notoriously cruel watchman at Treblinka extermination camp.

Vinko Pintarić (3 April 1941 – 25 May 1991) was a Croatian serial killer and outlaw who murdered five people over the course of 17 years and escaped from prisons and police stakeouts on multiple occasions. His violent, vindictive nature and proficiency with firearms struck fear into inhabitants of Hrvatsko Zagorje, a region of northern Croatia where he spent years at large, hiding from law enforcement and engaging in various crimes, until his 1991 death in a shootout with the police.

Gennady Grigorievich Serebrennikov (Russian: Геннадий Григорьевич Серебренников; born 3 April 1958) is a Russian serial killer and former major of the Ministry of Internal Affairs, who killed 5 witnesses related to his son's 2003 trial.

Dylann Storm Roof (born April 3, 1994) is an American mass murderer, white supremacist, and neo-Nazi who perpetrated the Charleston church shooting. During a Bible study on June 17, 2015, at Emanuel African Methodist Episcopal Church in Charleston, South Carolina, Roof murdered nine people and injured a tenth, all African Americans, including senior pastor and state senator Clementa C.

Bruno Lüdke (3 April 1908 – 8 April 1944) was a German alleged serial killer. Police officials connected him to at least 51 murder victims, mainly women, killed in a 15-year period, which began in 1928 and ended with his arrest in 1943.

The Cleveland Elementary School shooting took place on January 29, 1979, at Grover Cleveland Elementary School in San Diego, California, United States. The principal and a custodian were killed; eight children and a police officer were injured.

Roberto Succo (3 April 1962 – 23 May 1988) was an Italian serial killer who committed several murders and other violent crimes mostly in Italy and France in the 1980s.

In May 2012, Jun Lin (Chinese: 林俊; pinyin: Lín Jùn; December 30, 1978 – May 24 or 25, 2012), a Chinese university student, was fatally stabbed and dismembered in Montreal, Canada, by Luka Rocco Magnotta, who then mailed Lin's hands and feet to elementary schools and federal political party offices. After a video that showed Magnotta mutilating Lin's corpse was posted online, Magnotta fled Canada, becoming the subject of an Interpol Red Notice and prompting an international manhunt.