Of course, being accurate isn't as easy as it sounds. We novelists have enough on our hands, what with creating believable characters, an interesting crime, motives, and all of the other elements of the novel. It's sometimes hard to remember that accuracy matters. But it does. Mystery readers want authentic stories, and they sometimes complain if those stories play with the facts. In Agatha Christie's Cards on the Table, fictional sleuth and writer Ariadne Oliver puts it quite well:
To most people, though it matters. So it's important to do one's homework and find out facts. Many of us novelists use our own backgrounds to do that. Patricia Cornwell, for instance, has used her background in forensics brilliantly to make her Kay Scarpetta series authentic. Robin Cook's medical background has given him a lot of useful knowledge about the world of medicine. In fact, Cook was trained as an ophthalmologist, and you can see his technical accuracy in books such as Blindsight. Kevin Hughes uses his experience as a former police officer to add acccuracy to Dogging the Truth and Casualty Crossing. Agatha Christie spent World War I working in the dispensary of a Voluntary Aid Detachment Center. That experience gave her a great deal of knowledge of poisons, which she used so well in books such as Murder in Three Acts (AKA Three-Act Tragedy), Peril at End House, The Mysterious Affair at Styles, Sad Cypress and Poirot Loses a Client (AKA Dumb Witness).