Calling all amateur sleuths: These cold cases are begging to be solved.

Cold cases are some of the most fascinating of all true crime stories because they emulate a puzzle that has yet to be solved. They shed light on unsolved cases that have mystified law enforcement, lying dormant until a skilled detective or a true crime junkie comes along and solves it. These books present you with all the necessary details of a case and possibly offer a potential explanation. The appeal is in the potential. With fresh eyes, new ideas, and steadfast determination on an unsolved case, closure is always a possibility.

Delving into the most famous cold cases of all time, it becomes frustratingly clear that as more time passes, the less likely it is to be solved. Physical evidence in cases gets lost to time, and key suspects and witnesses pass away. Like the infamous Zodiac Killer of the late 1960s, who sent coded letters and ciphers to the police after murdering his victims. Despite countless investigations and several suspects, the case remains cold, with little evidence to crack it. Or the murder of young beauty queen JonBenét Ramsey in 1996, whose case was so badly mishandled by the police that no suspect was ever prosecuted and is still being investigated today.

New advances in forensics and crime-solving technologies can help close cold cases, but it's often not enough to bring justice to victims. Maybe you’ve got what it takes to unravel the mind of a criminal, find out what went wrong, and solve a cold case.

If you’re a fan of this mystifying sub-genre, here are some taunting good stories to start investigating:

• These unsolved true crime cases haunt our readers
• Cold true crime cases that were recently solved with new forensics
• Books about cold cases that finally got solved

And after you’ve worked your way through those, browse the stories below to discover the cold cases that continue to shock the world and puzzle law enforcement.