Jack the Ripper's suspected true identity will be revealed later, more than 100 years after his gruesome series of murders terrified London.
The killer was never caught and there have been countless investigations, books, articles, plays, films and musicals based on the murders.
Now, documents from the original investigation have been discovered by a descendant of the officer in charge of the case in 1888.
The papers from Chief Inspector Donald Swanson shed new light on the notorious case and are said to contain the name of the person suspected of the crimes.
They are being loaned to Scotland Yard's Crime Museum - the oldest of its kind in the world - for its relaunch today.
At least five women - all prostitutes - were killed by the Ripper and there are several theories as to his identity.
His victims were either strangled or stabbed, with some of the bodies badly mutilated and even having organs removed. Some believed he had medical training.
Until now, those in the frame have included an employee of the Royal Family, an artist and a man called Francis Tumblety who was arrested shortly after the last killing but escaped to the US.