Now, 75 years later, historian Paul French has retraced the detectives' footsteps. With the publication of his new historical novel, Midnight in Peking, French has given Pamela a form of belated justice - something she was denied for so long.
He first read of Pamela's story in American journalist Edgar Snow's biography. She was the 19-year-old daughter of Edward Theodore Chalmers Werner, a former British consulate general and old China hand. Intrigued, he headed to the newspaper archive in London's British Library.
"As soon as I got hold of her pictures, she became a person to me," French says. "She had her whole life ahead of her, but someone stepped in, murdered her and moved on without getting arrested or convicted."
Reports written at the time by two British and Chinese police inspectors led French to a few suspects among the then-3,000-strong foreign community living in Beijing's Legation Quarter and Badlands. They included Pamela's father, American dentist Wentworth Prentice, and a member of a Russian criminal underclass, known as "Pinfold".
The first two men were part of Legation Quarter's high society, and well-documented in photos, memoirs and newspaper reports. But finding information about "Pinfold", who lurked in the crime-and-drug-infested Badlands, proved difficult. "It was an area nobody wanted to admit existed," French says. "Little was known about the low life, driftwood and underworld."
However, French had a stroke of luck after tracking down some of Pamela's former schoolmates, who are now in their 90s. The elderly women provided him with interesting gossip about the case. "Official accounts don't tell you what was being whispered in the clubs and schoolrooms of the time - the false allegations, the assumptions, and the fear," he said.
A breakthrough came when French found boxes of documents from Beijing in 1943, which had piled up in Britain's National Archives.
One box held the 150-page report of the private investigation by Pamela's father. "Werner spent his life savings to pay people to talk to him and hire Chinese detectives," French said. "When I cross-referenced his report with the police investigation and autopsy, I found he had already known whodunnit, but London [in 1943] had bigger concerns, like winning the war."
Meticulous research helped French bring the sequence of events to life in his book. He used descriptions and dialogues from real documents, such as autopsy reports and newspapers. "I footnoted the book for anyone who doesn't believe any conversation, event or clue," he said. "I read widely and looked at old photos to get things right, like the lack of electric street lights in most of Peking plunging the city into darkness every night."
French was surprised to solve the mystery, but was even more shocked to find how the horror of Pamela's violent death mirrored the changes in the last days of old Beijing. He found the police, even the British consulate, put obstacles in the way of justice for Pamela.
"Stalin said one death is a tragedy and a million a statistic," French said. "Her unsolved murder symbolises how China slipped from civilisation to barbarism in a matter of months. After Pamela's death, so many innocent lives were to be disrupted and ended violently, too."
For details on Midnight in Peking go to www.midnightinpeking.com
Young Post met French at a Royal National Geographic Society lecture; www.rgshk.org.hk