1. The Brabant Killers Belgium’s most notorious unsolved crime spree, between 1982 and 1985 a series of violent attacks left 28 dead and 40 injured.

2. The Original Nightstalker This serial killer was active in California between 1979 and 1986. He raped at least 50 women and murdered 10 people.

3. The Icebox Murders After Charles Rogers murdered and dismembered his abusive father and mother, he disappeared and was never heard of again. The police found his parents in their freezer.

4. West Mesa Murders This refers to the case of 11 women being found buried in the desert outside of Albuquerque, New Mexico in 2009. No suspects have been named.

5. Zodiac Killer This was a serial killer that operated in northern California during the 60s and 70s. His name came from several cryptic messages that he sent to the local press.

6. Chicago Tylenol murders In 1982 several people were poisoned and died when they swallowed tylenol capsules that had been laced with potassium cyanide.

7. Jack the Ripper Possibly the most famous unsolved crime, this English serial killer has haunted the collective imagination for more than a century.

8. Villisca Axe Murders On the night of June 9, 1912, the Moore family was bludgeoned to death with an axe in the small town of Villisca, Iowa. One suspect was tried twice but acquitted.

9. Annecy Shootings High in the French Alps, nearly the entire family of Iraqi-born British tourist Saad al-Hilli was killed by a sniper in 2012. Nobody has been convicted.