It has to be believable.
22 years ago, four people were beaten to death in a hotel in Huzhou, Zhejiang Province, China. The police believe that two men committed the crime: they had checked into the hotel intending to rob other occupants and were caught by another guest. They apparently beat that guest to death, along with the hotel owners and the owner’s grandson.
This became a cold case until earlier this year, when the police were able to do more sophisticated DNA analysis. They eventually narrowed the pool of suspects down to two men, a Mr. Wang and Liu Yongbiao. Both have been arrested, and Mr. Liu has apparently confessed.
The twist? Mr. Liu went on to become a moderately successful Chinese mystery writer.
In the preface to his 2010 novel “The Guilty Secret,” the Chinese author Liu Yongbiao expressed his desire to write a suspense-filled detective story about an alluring female writer who dodges arrest despite committing a string of murders.
“I came up with the idea after reading some detective novels and watching crime shows and movies,” Mr. Liu wrote at the time. “The working title is: ‘The Beautiful Writer Who Killed.’”
(As far as I can tell, “The Guilty Secret” is not available in a US edition.)
You put that into a novel these days, people will just roll their eyes and say, “Yeah. Right.”