Criminal investigators, journalists, and authors have considered some heists, hijackings, and even murders as “perfect crimes.” In these instances, the criminals left no evidence at the scene, or the execution of the crimes prevented authorities from ever solving the cases. A "perfect crime" is an unsolvable crime, but not due to any incompetence of investigators. The term delineates a criminal action in which the perpetrator deliberately left no evidence behind - and in extreme cases, the crimes themselves are undetectable.
Unsolved robberies - whether the target is a bank, museum, or jeweler - can reflect orchestrated schemes out of a movie like Ocean’s 18. Unsolved murders, particularly those that involve unidentified serial killers, may reflect the time period’s limited forensic capabilities. In other instances, the murders are unsolvable due to lack of evidence, motive, and even a body.
These 18 well-known crimes reflect the actions of robbers and murderers whom police will likely never identify - and capture.
The 300 Million Yen Robbery
On December 10, 1968, a policeman on a motorcycle pulled over a Tokyo-based Nihon Shintaku Ginko Bank car that was transporting Toshiba employee bonuses. Reportedly, the officer warned the four passengers in the car that there was a bomb planted underneath, and they quickly vacated the vehicle, leaving the uniformed patrolman to crawl under the car. Moments later, smoke and flames poured out of the bottom, causing the occupants to run. Then the faux cop jumped into the bank car and drove off with the money, which amounted to 300 million yen, or approximately $817,000 for the time.
The investigation included an exhaustive list of evidence and suspects, and over 170,000 police detectives were active in the case. In 1975, the statute of limitations ended. Tokyo authorities never identified the robber who impersonated an officer. The case became the most famous heist in Japanese history.
The Murder of Ken Rex McElroy
In 1981, at least two people shot and killed Ken Rex McElroy. Reportedly, the community of Skidmore, MO regarded McElroy as bully and terror. The shooting occurred in the middle of the day, in full view of dozens of people. McElroy's slate of crimes included dozens of felony charges for robbery, assault, attempted murder, child molestation, cattle rustling, and finally, shooting a man in the neck with a shotgun.
Authorities never prosecuted McElroy for his crimes, which the townspeople of Skidmore lamented to journalists. When police began investigating his murder, no one came forward to give evidence. While McElroy’s widow identified a man she thought was one of the shooters, the witnesses were not willing to corroborate her testimony, and the case remained unsolvable.
D.B. Cooper's Hijacking
On Thanksgiving Eve, 1971, a hijacker under the alias “Dan Cooper” boarded a Northwest Airlines flight in Portland, OR, wearing a suit and tie. Once the flight was in the air, he ordered a drink and passed a note to the stewardess, which read: "I have a bomb in my briefcase. You are being hijacked." He demanded $200,000, two parachutes, and a fuel truck.
When the plane landed in Seattle, Cooper exchanged the hostages on the plane for the money and parachutes and then ordered the plane to take off again. A half hour into the flight, Cooper deployed the back stairs of the airplane and jumped out.
An exhaustive investigation turned up no clues as to where Cooper - who a local news story misidentified as "D.B. Cooper" - or the money wound up. Years later, authorities recovered a portion of the money near the Columbia River. The FBI stopped pursuing the case in 2016.
Banco Central Tunnel Heist
In 2005, authorities investigated Brazil’s largest bank robbery to date. A group of Brazilian burglars disguised as a landscaping company dug a tunnel of approximately 200-meters under the vault of Fortelaza’s Banco Central. After three months of digging, the gang crawled beneath two city blocks to the bank, blasted their way through a meter of steel-reinforced concrete, and emptied out the vaults.
They stole an amount of nearly $72 million. In 2001, Brazilian authorities reportedly apprehended over half of the 35 gang members involved in the heist, yet only recovered a small percentage of the stolen money. The Guinness Book of World Records named the Banco Central Heist as the “Greatest robbery of a bank.”