20th-century American criminals

Jeffrey Lionel Dahmer (; May 21, 1960 – November 28, 1994), also known as the Milwaukee Cannibal or the Milwaukee Monster, was an American serial killer and sex offender who killed and dismembered seventeen males between 1978 and 1991. Many of his later murders involved necrophilia, cannibalism, and the permanent preservation of body parts—typically all or part of the skeleton.Although he was diagnosed with borderline personality disorder (BPD), schizotypal personality disorder (StPD), and a psychotic disorder, Dahmer was found to be legally sane at his trial. He was convicted of fifteen of the sixteen homicides he had committed in Wisconsin and was sentenced to fifteen terms of life imprisonment on February 17, 1992. Dahmer was later sentenced to a sixteenth term of life imprisonment for an additional homicide committed in Ohio in 1978.
On November 28, 1994, Dahmer was beaten to death by Christopher Scarver, a fellow inmate at the Columbia Correctional Institution in Portage, Wisconsin.

Eric David Harris (April 9, 1981 – April 20, 1999) and Dylan Bennet Klebold ( KLEE-bohld; September 11, 1981 – April 20, 1999) were American high school seniors who perpetrated the Columbine High School massacre at Columbine High School on April 20, 1999 in Columbine, Colorado. Harris and Klebold killed 12 students, one teacher, and wounded 24 others. After killing most of their victims in the school's library, they died by self-inflicted gunshot wounds. At the time, it was the deadliest high school shooting in U.S. history.The ensuing media frenzy and moral panic led to "Columbine" becoming a byword for school shootings, and becoming one of the most infamous mass shootings ever perpetrated in the United States.Harris and Klebold were both born in 1981. Harris was born in Wichita, Kansas, but moved around frequently as a child due to his father's occupation in the United States Air Force, while Klebold was born and raised near Columbine. Harris's family eventually settled in Colorado in 1992. Shortly after, Harris and Klebold met while they were in the 7th grade. Over time, they became increasingly close. By the time they were juniors in high school, they were described as inseparable. There are differing reports; some say Harris and Klebold were very unpopular students once they were upperclassmen, as well as frequent targets of bullying, while others say they were not near the bottom of the school's social hierarchy and that each had many friends, along with active social lives. Columbine High School was known to have an intense "jock culture", which saw popular students, mainly athletes, benefit from special treatment from faculty and other students.According to their journal entries, Harris and Klebold had seemed to begin planning the attack by May 1998, nearly a year before the attack. Throughout the next eleven months, Harris and Klebold meticulously built explosives and gathered an arsenal of weapons. Both Harris and Klebold each left behind several journal writings and home videos, ones they made both alone and together, foreshadowing the massacre and explaining their motives. Harris and Klebold hoped this content would be viewed by the public extensively and inspire followers, although much of the evidence has never been released by authorities.
Harris and Klebold often wore trench coats in school, and in general, as part of their everyday outfits, so after the massacre, it was widely believed Harris and Klebold were part of a clique in school called the "Trenchcoat Mafia", a group of misfits in the school who supposedly rebelled against the popular students. This turned out to be untrue, as neither Harris nor Klebold had any affiliation with the group. The pair's aforementioned writings and videos gave insight into their rationale for the shooting. The FBI concluded that Harris was a psychopath, who exhibited narcissistic traits, unconstrained aggression, and a lack of empathy, while Klebold was concluded to be an angry depressive with a vengeful attitude toward individuals who he believed had mistreated him. However, neither Harris nor Klebold were formally diagnosed with any personality disorders prior to the attack, so this conclusion is often debated. In the following years, various media outlets attributed multiple motivating factors to the attack, including bullying, mental illness, racism, psychiatric medication, and violence in music, movies, and video games. Despite these conclusions, the exact motive for the attack remains inconclusive.
Harris and Klebold have become pop culture icons, with the pair often portrayed, referenced and seen in film, television, video games, music and books. Many killers since the shooting have taken inspiration from the pair (dubbed the Columbine effect), either hailing them as heroes, martyrs and gods, or expressing sympathy for them. Harris and Klebold also have a fanbase, who have coined the term "Columbiners", who write fan fiction and draw fan art of them. Others have also dressed as the duo for cosplay or Halloween.

Theresa Jimmie Francine Knorr (née Cross; born March 14, 1946) is an American woman convicted of torturing and murdering two of her six children while using the others to facilitate and cover up her crimes. She was acquitted of murdering her first husband and was also considered a suspect in the unsolved murder of her sister. She is currently serving two consecutive life sentences at the California Institution for Women in Chino, California.

Ronald Clark O'Bryan (October 19, 1944 – March 31, 1984), nicknamed The Candy Man and The Man Who Killed Halloween, was an American man convicted of killing his eight-year-old son Timothy (April 5, 1966 – October 31, 1974) on Halloween 1974 with a potassium cyanide-laced Pixy Stix that was ostensibly collected during a trick or treat outing. O'Bryan poisoned his son in order to claim life insurance money to ease his own financial troubles, as he was $100,000 in debt. O'Bryan also distributed poisoned candy to his daughter and three other children in an attempt to cover up his crime; however, neither his daughter nor the other children ate the poisoned candy. He was convicted of capital murder in June 1975 and sentenced to death. He was executed by lethal injection in March 1984.

Benjamin Hoskins Paddock Jr. (November 1, 1926 – January 18, 1998) was an American bank robber and con man who was on the FBI Ten Most Wanted Fugitives list from 1969 to 1977. He was the father of mass murderer Stephen Paddock, the perpetrator of the 2017 Las Vegas shooting.

Leslie "Joe Goebbels" Irvin (April 2, 1924 – November 9, 1983) was an American serial killer whose killing spree in the early 1950s terrorized residents of southwestern Indiana and whose Supreme Court case set a precedent for ensuring a fair trial for defendants even in the wake of a great deal of pretrial publicity.

Charles Howard Schmid Jr. (July 8, 1942 – March 30, 1975), also known as the Pied Piper of Tucson, was an American serial killer whose crimes were detailed by journalist Don Moser in an article featured in the March 4, 1966, issue of Life magazine. Schmid's criminal career later formed the basis for "Where Are You Going, Where Have You Been?", a short story by Joyce Carol Oates.: 9  In 2008, The Library of America selected Moser's article for inclusion in its two-century retrospective of American true crime literature.

Ernesto Arturo Miranda (March 9, 1941 – January 31, 1976) was an American laborer whose criminal conviction on kidnapping, rape, and armed robbery charges based on his confession under police interrogation was set aside in the landmark U.S. Supreme Court case Miranda v. Arizona, which ruled that criminal suspects must be informed of their right against self-incrimination and their right to consult with an attorney before being questioned by police. This warning is known as a Miranda warning.
After the Supreme Court decision invalidated Miranda's initial conviction, the state of Arizona tried him again. At the second trial, with his confession excluded from evidence, he was convicted. He was sentenced to 20–30 years in prison.
On January 31, 1976, Miranda was stabbed to death in Phoenix, Arizona. A Mexican man, Eseziquiel Moreno Perez, was charged with the murder of Miranda, but fled to Mexico and has never been located.

Charles Frederick Albright (August 10, 1933 – August 22, 2020) also known as the Eyeball Killer, was an American murderer and suspected serial killer from Texas who was convicted of killing one woman and suspected of killing two others in 1991. He was incarcerated in the John Montford Psychiatric Unit in Lubbock, Texas.

Nathaniel Benjamin Levi Bar-Jonah (born David Paul Brown; February 15, 1957 – April 13, 2008) was an American convicted child molester and suspected cannibalistic serial killer who was sentenced to 130 years in prison without the possibility of parole after being convicted of the kidnapping, aggravated assault, and sexual assault of various children.