From the first case solved thanks to a fingerprint in 1905 to the ropes used to hang prisoners, a new exhibition in London displays hundreds of exhibits kept under wraps by Scotland Yard until now.
A poisoned syringe belonging to the Kray twins, notorious London gangsters from the 1960s, and the handwritten notes of the chief detective in the case of Jack the Ripper are also included in the show.
"The Crime Museum Uncovered" opens on Friday and runs until April 10, bringing together 600 of the 2,000 ghoulish objects accumulated since the mid-19th century at London police headquarters.
Until now the displays have only been seen by special guests such as Sherlock Holmes author Arthur Conan Doyle and generations of police officers doing their training, the show's co-curator Jackie Kelly said.
The idea is to show the public how the police operate and the evolution of crime-catching techniques, as well as shine a light on the victims.
"We remember the criminals, not so often the victims," Kelly said.
One particularly sinister murder case documented is that of Emilie Kaye in 1924, which led to the introduction of compulsory kits for investigators including gloves and specialized instruments to avoid contaminating evidence at the scene of a crime.
The young woman was lured by her lover to a cottage in southern England for a romantic assignation.
Once she arrived, she was killed and cut into pieces.
It was also after this case that photography was banned in courtrooms because the image of her murderer when he was sentenced to death had shocked the public.
There are also the first televised images from 1911 of an assault by the police on a building in east London where some robbers had gone into hiding.
In the early film reel is future prime minister Winston Churchill, then the interior minister.
The exhibition also contains the story of Ruth Ellis, who was sentenced to death in 1955 for murdering her lover. She was the last woman ever executed and the case launched a debate about capital punishment.
British MP's in 1965 voted to suspend the death penalty, which was definitively abandoned in 1969.
Knives and guns feature in the exhibition, along with the memoirs of Donald Swanson who chased after Jack the Ripper in the 1880s.
There are also the death masks of people executed in the 19th century, which were preserved to measure the size of their brains and keep a record of their faces.
The museum insisted it was not glorifying crime or criminals.
"We did not want a sensational display. There are no human remains, we respect the dignity of the victims," said Annette Day, senior curator of the museum.
Martin Hewitt, assistant commissioner at the Metropolitan Police, said: "Under no circumstances did we want the museum to glamorize crime, or the criminals involved".