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Ma Barker -

Ma Barker is one of the most famous criminals in the history of the United States. At the beginning of the 1930s, Barker planned numerous robberies, murders, and kidnappings with the Barker Gang, which included her two sons. In 1935, she was killed by the FBI in the house where she was hiding. Curious sightseers still visit the house.

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Mary I of England - Known as Bloody Mary, the Queen of England was responsible for the persecution of Protestants and the death of more than 300 people.

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Mireya Moreno Carreon -

Mireya Moreno Carreon was a drug trafficker for the Los Zetas cartel in Mexico. She used to be a police officer, until she joined the cartel and became a head of the organization. She was arrested in 2011.

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Myra Hindley - Hindley, accompanied by her boyfriend Ian Brady, killed five children between the ages of 10 and 17 in England in the 1960s. She was sentenced to two life sentences, and died aged 60 in 2002.

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Klara Mauerova -

This Czech woman belonged to a religious cannibal cult. Along with other members, she tortured one of her children, forcing him to perform self-cannibalization. Mauerova was sentenced to nine years in prison in 2008.

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Juana Barraza - Born in 1957, she was a professional wrestler and one of Mexico's most famous killers. Juana Barraza killed between 42 and 48 elderly women. She was arrested in 2006, and condemned to 759 years in prison.

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Darya Saltykova -

She was a noblewoman and serial killer in 18th-century Imperial Russia. She tortured and murdered more than a hundred serfs.

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Griselda Blanco - This Colombian woman was a famous drug trafficker and one of the main players in the Medellín Cartel. Blanco is thought to be responsible for more than 200 murders.

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Amelia Dyer -

Born in Bristol, England in 1837, Amelia Dyer was an infamous killer. Over the course of 20 years, she is thought to be responsible for the murder of hundreds of children. She was detained in 1869 and later hanged.

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Delphine LaLaurie - This New Orleans woman tortured and murdered her household slaves. When she was discovered, she fled to France.

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Christiana Edmunds - This English woman used to buy chocolates, fill them with strychnine, and then return them to the store for others to purchase. In 1871, a child died after eating some of these poisoned chocolates. Edmunds was condemned to death, however later the sentence was reduced to life in prison.

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Miyuki Ishikawa - During the 1940s, the midwife (pictured covering face) willfully neglected children whose parents couldn't afford to keep them. She later started asking for money from them, justifying that it cost less than raising a child would have. She is thought to have killed more than 100 infants. During trial she blamed the parents for abandoning them, and was sentenced to just eight years in prison.

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Gertrude Baniszewski - This American woman tortured a girl to death. Later, it was discovered that she committed the crime with the help of her children and four other neighborhood kids. In 1965 she was convicted of first-degree murder.

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Karla Homolka -

Along with her husband, Paul Bernardo, this Canadian woman kidnapped, sexually assaulted, and killed two young women in the early 1990s. It was later revealed that they were responsible for the sexual assault and death of her own sister as well. Karla Homolka was later released in 2005 for testifying against her now ex-husband. She changed her name and was relocated to Guadalupe. She eventually returned to Quebec with her three kids.

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Ilse Koch -

Koch (pictured testifying) was the wife of a commander at the Buchenwald concentration camp. She beat prisoners, forced them to do unthinkable things, and abused those with tattoos.

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Aileen Wuornos - Aileen Wuornos was an American sex worker who killed seven men between 1989 and 1990. She was executed by lethal injection in 2002.

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Ranavalona I -

Ranavalona I ruled the island nation of Madagascar for over 33 years. She's considered one of the cruelest leaders of all time. Thousands of people died under her strict and brutal regime.

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Belle Gunness - Also known as the Black Widow, Belle Gunness was born in 1859 in Norway. After emigrating to the US, she killed two husbands and all of her children. It is thought that she killed more than 40 people in total.

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Dagmar Overbye - This Danish serial killer is thought to have killed more than 25 children between 1913 and 1920. In 1921, she was condemned to death. That sentence was later reduced to life in prison. She died in 1929.

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Catherine de' Medici - This Italian noblewoman was queen consort of France from 1547 until 1559. Some say she was the mastermind of the St. Bartholomew's Day Massacre. It is estimated that she killed thousands of people on that occasion.

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Leonarda Cianciulli - Between 1939 and 1940, Leonarda Cianciulli murdered three women and made cakes and soap out of their remains. She allegedly committed these crimes to break a curse on her family.

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Irma Grese - Irma Grese (middle) was an SS guard at Ravensbrück and Auschwitz concentration camps. She was in control of around 30,000 prisoners, whom she tortured physically and psychologically. Grese wore jackboots and always had a pistol and a whip on her. She was hanged for her crimes by the Allies at just 22 years old.

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Charlene Gallego -

Alongside with her husband Gerald Gallego, Charlene killed 10 people between 1978 and 1980. She was sentenced to 16 years in prison, but was later freed after testifying against her husband.

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Elizabeth Báthory - Nicknamed the Blood Countess or Countess Dracula, Báthory was a Hungarian countess who tortured and killed hundreds of young women at the turn of the 16th century. She liked to bathe in the blood of her victims, which she believed kept her young.

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Tillie Klimek -

This Polish-American serial killer was active in Chicago during the first half of the 20th century. Between 1912 and 1923, she poisoned nearly 20 people with arsenic. Some victims recovered, while others, including all four of her husbands, died. In 1923 she was sentenced to life in prison.

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