An e-fit showing what detectives believe serial killer Jack the Ripper looked like has been revealed.
The case has fascinated people for decades
Using new profiling techniques, investigators have created a picture of what they believe the 19th Century murderer would have looked like.
The man, who evaded police in the 1880s, is thought to have killed and mutilated five London prostitutes.
The Scotland Yard team describe him as "frighteningly normal" but someone capable of "extraordinary cruelty".
And investigators have admitted that police at the time were probably searching for the wrong kind of man.
Head of analysis for Scotland Yard's Violent Crime Command Laura Richards, who has studied serial killer Fred West and Soham murderer Ian Huntley, revisited the case using modern police techniques.
She brought together a team of experts, including pathologists, historians and a geographical profiler, to find out if the case could ever be solved.
The result has been the most accurate physical, geographical and psychological portrait of the Ripper ever put together.
It will be revealed in a documentary on the TV channel Five on Tuesday.
Ms Richards said the 118-year-old evidence shows the Ripper was between the ages of 25 and 35, between 5ft 5ins and 5ft 7ins tall. He was also of stocky build.
Investigators have even been able to pinpoint his address.
Ms Richards said: "For the first time, we are able to understand the kind of person Jack the Ripper was.
"We can name the street where he probably lived; and we can see what he looked like; and we can explain, finally, why this killer eluded justice."
Metropolitan Police Commander John Grieve, who has worked with the team of experts, believes the killer would have been caught if officers at the time had this new information.
"This is further than anyone else has got," he said. "It would have been enough for coppers to get out and start knocking on doors... they would have got him."
Dubbed Britain's first serial killer, the Ripper is believed to have killed at least five prostitutes in Whitechapel, east London, in 1888, but was never caught.
His victims were stabbed, with some of the bodies badly mutilated and even having organs removed. Some believed he had medical training.
The pseudonym Jack the Ripper was coined from a letter sent to a London news agency at the time of the murders, supposedly from the killer himself, but which police later dismissed as a hoax.
Suspects have included Lewis Carroll, Prince Albert Victor and Sir John Williams, obstetrician to the Royal Family.
The identity of the serial killer was never discovered
Using their experience of modern-day crime to examine 13 different witness statements taken at the time of the killings, the team were left with a picture of someone Ms Richards described as "perfectly sane, frighteningly normal, and yet capable of extraordinary cruelty".
Mr Grieve added: "It's a popular misconception that nobody ever saw the murderer, that he just vanished into the fog of London.
"Well that's just not right. There were witnesses at the time who were highly thought of by the police.
"If we were doing this investigation today, we could pool together all these descriptions and the kind of face that the police were clearly looking for.
"You could come up with a composite and you can go beyond just a full face, you can get something that really helps the police to look for suspects."