#3 Jack the Ripper Murders
Perhaps one of the most infamous murderers in history, Jack the Ripper is well known for attacking in the poor areas of the Whitechapel district in London in 1888. His victims were usually female prostitutes who got their throats slit and their abdomens mutilated. Although many speculations remain as to Jack the Ripper’s identity, finding this out becomes more and more unlikely as more time passes by.
#4 JonBenét Ramsey
A more recent case, JonBenét Ramsey, a child beauty pageant contestant, was murdered in 1996 in her home in Boulder, Colorado. Only 6 years old, her body was found in the basement of her house, just 8 hours after her parents reported she was missing. JonBenét was struck on the head and strangled. There is a theory that the child could have died at the hands of her parents and brother—but DNA evidence on JonBenét’s clothes say otherwise. Even when a former schoolteacher, John Mark Karr confessed in 2006 to being involved in her death, his DNA was not a match. Her DNA records are still in storage, waiting for a match to find her killer.