HE story of Burke and Hare's notorious Edinburgh crimes has survived for nearly 200 years.
In that time it has spawned books, films and a string of city tours, and next year their chilling tale will get another re-telling, when David Tennent is due to begin filming yet another movie based on their exploits.
Everyone knows the story. The problem, argues the historical detective behind a new book examining their deeds, is how much of what they know is actually true?
History professor Lisa Rosner, who lectures at Stockton University in New Jersey, US, has carried out a fascinating 'CSI' style investigation into the pair, delving into long-forgotten documents and ploughing through dusty city archives in a meticulous search for the truth.
Her remarkable discoveries – told in her new book, The Anatomy Murders – unravelled poignant details which bring to 'life' the personalities of some of the pair's unfortunate and, until now, largely anonymous victims.
Her findings, she confesses, startled even her and at one stage left her gasping with surprise.
"The story has been recycled so many times with parts added in, that the truth has become a bit lost, so it's been fascinating establishing the fact from the fiction.
"What has come out is not only more truthful, but a little bit seedier and even more creepy."
She decided to investigate the pair's killing spree after stumbling across previously unexamined diaries written by an Edinburgh physician she was researching for an earlier book.
During one trip to the City Chambers, she ploughed through documents hardly touched for two centuries and could hardly contain her amazement at what she found.
"The popular story goes that one of Burke and Hare's victims was a beautiful prostitute called Mary Patterson. I believed just like everyone else, the story that she was identified as she lay on anatomist John Knox's table by a young student who had used her services. I decided to look for her," explains Prof Rosner.
Mary's story started to unravel when the professor uncovered not one but a series of etchings all claiming to show Mary but each depicting a different woman.
"I went through the records of the Edinburgh Magdalene Asylum, which was a cross between a refuge and a reform school for girls who had been led astray.
"I didn't expect to find her – by all accounts she was a well-known, fairly notorious prostitute.
"Then I turned a page dating from 1826, and there she was. I really almost did start crying."
The discovery brought Mary to 'life', final proof that despite popular belief, the real Mary wasn't a working prostitute but instead was a young woman trying desperately to turn her life around.
Prof Rosner kept turning the pages until 18 months later Mary appeared again, this time being discharged from the asylum presumably into what she hoped would be a stable future. The date, however, left Prof Rosner reeling.
"The date of the entry was 8 April, 1828.
"I stared at that date and gasped. I went back to my notes and sure enough, that was one day before she was murdered."
That discovery, along with various others concerning the murderous pair's 16 victims, brings the characters to life, says Prof Rosner. It also revealed a relevance to today, she adds.
"Although all this happened a long time ago, what struck me was that this was such a modern crime, not only because it was linked to scientific research but because Edinburgh was such a modern place at that point, with its police force and the use of forensics," she says.
"It's been fascinating to delve into the story and find there's much more to it than what usually gets told."
The Anatomy Murders by Lisa Rosner is published by University of Pennsylvania Press.