- The youngest victim of Joachim Kroll, the cannibal-killer from Germany, was just four years old. Her name was Marion Ketter.
- The Red Ripper was sexually aroused by killings, leading him to a maniacal death spree that took 53 victims.
- Petr Zelenka murdered people by injecting them a lethal dose of heparin - a drug that creates internal bleeding.
7. Roger Andermatt
Andermatt was a killer who committed his murders while he was working as a nurse in homes for the elderly. This most infamous serial killer ever to appear in Switzerland was known as the Death-Keeper of Lucerne, with Lucerne being his hometown. All of his victims, 22 of them were residents of nursing homes between 66 and 95 years of age.
Andermatt would first administer his victims with a deadly dose of tranquilizer, and suffocate them with plastic bags. In 2005, Andermatt was sent to spend his life in prison. Andermatt would enter homes pretending to be a dance teacher and a DJ under alias R.O.Gee.
6. Péter Kovács
Infamously known as the Monster of Martfu, Kovács was a killer from Hungary. He was a stalker and a sexual predator who strangled five women from 1957 to 1967. He also physically abused all of his victims.
Szolnok County Court executed Péter Kovács by hanging on December 1, 1968. After the Hungarian police found out who was the killer, they could release a man named Janos Kirjak, who was wrongfully accused of killing Kovács’ first victim - Margit Szegedi. Kirjak spent 11 years in prison.
5. Dennis Nilsen
From 1978 to 1983, this horrific serial killer from Scotland killed 15 men. Nilsen would pick up men in the city of Fraserburgh, after which he would either strangle or drown his victims. After that, he would have sex with the corpses. He was sentenced to spend his life in prison and died in jail in Yorkshire in 2018.
4. Petr Zelenka
Another killer that made his killings in the hospital facility where he worked was Petr Zelenka from the Czech Republic. In 2006, between May and September, Zelenka went on a killing spree that left seven people dead. He would secretly inject the patients with a drug called heparin, which can cause internal bleeding if the dose was large enough. Zelenka was arrested in 2006, put to trial, and found guilty. From 2008, Petr Zelenka is serving a life sentence in prison.
3. Harold Shipman
This British doctor was found guilty for killing his patients and was convicted to life in prison on January 31, 2000. Shipman got his life sentence when he was found guilty of killing 15 people. However, it is estimated that the death toll is shockingly more significant. From 1975 and 1998, Shipman examined a lot of patients that died after his deadly treatment, and the possible death count could be bigger than 250 people. Shipman died in his prison cell, one day before his 58th birthday.
2. Andrei Chikatilo
Also known as the Red Ripper or the Butcher of Rostov, this Russian serial killer is responsible for killing more than young women and children. His killing spree lasted for 12 years, from 1978 to 1990, during which he brutally stabbed and slashed 53 people. When he faced trial, Chikatilo said how the only way to achieve sexual arousal was to stab women. In 1994, he was executed by a firing squad.
1. Joachim Kroll
This serial killer from Germany was active for 21 years, continually escaping police and their sloppy ways of investigation. Kroll started his killings in 1955 and continued to do so up until 1977. His victims were young girls and boys, and the nature of the crimes was heinous.
Kroll brutally assaulted, mutilated, raped, and ate parts of the flesh of his victims. The youngest victim on his list was just four years older: Marion Ketter, whose body parts were found in Kroll’s apartments. Joachim Kroll was sentenced to serve a life sentence in prison after admitting that he did the same thing to 14 people. He died because of heart failure in 1991.