SCOTT SIMON, HOST:
There is no Sherlock Holmes without forensics. No Sam Spade, Philip Marlowe, Miss Marple, "No. 1 Ladies Detective Agency." No crime fiction, "Law And Order," Sara Paretsky, Lee Child, or Nick and Nora without forensic science bringing evidence - not just brute strength or bigotry - to bear in the criminal justice system. Val McDermid, who's written almost 30 books of crime fiction, many around a criminal profiler named Dr. Tony Hill, she has a new book, "Forensics: What Bugs, Burns, Prints, DNA And More Tell Us About Crime."
Val McDermid joins us from the studios of the BBC in Salford in the United Kingdom.
Thanks so much for being with us.
VAL MCDERMID: It's a pleasure.
SIMON: And I was fascinated - one of the first stories you relate is - do we need to call it an apparent murder, even these days - in China in 1247. What happened?
MCDERMID: There was a murder in the village, someone was hacked to death. And the local coroner looked at the wounds and decided that the wounds had been made by a sickle. And so he had everyone in the village who owned a sickle line up with their sickle on the ground in front of them. And at one particular sickle, a fly landed, and then another fly. And then there was a whole buzzing cloud of flies because although the man had tried to wash his sickle clean of blood, the flies could still smell those traces. And so the coroner concluded and deduced that this was the killer. Faced with this evidence, the man confessed. And that's the first recorded instance we have of forensic entomology.
SIMON: You have cautions in the book about DNA evidence. The quote I wrote down is - you quote an expert who says that the error rate is exceptionally low, but it's not zero.
MCDERMID: Yes, and that's the thing. Every scientific process always has a margin of error, so that's something one has to be bear in mind. And the other thing with DNA is that it is something of a double-edged sword. When DNA identification was first developed, you needed a blood stain the size of a quarter. Now we're at a point where you can get DNA from something that is a millionth the size of a grain of salt. And a lot of DNA is accidentally transferred. So if we were to meet for a drink, say, and I was to give you a hug and a peck on the cheek, my DNA would be on your face. My DNA would be on your jacket. If in the course of that evening someone else were to murder you in a very clean and neat way, I would be the suspect.
SIMON: Oh, boy. You know, when we meet for a drink (laughter), I'll bear that in mind.
MCDERMID: (Laughter).
SIMON: Wear rubber gloves and, you know.
MCDERMID: Yeah.
SIMON: I know a career prosecutor in Cook County, Ill. - Chicago - who says ever since the O.J. Simpson trial, she's had juries - I don't know if she's being apocryphal - she says she'd had juries in shoplifting cases who say, where's the DNA evidence?
MCDERMID: Yeah. It's become - I think - and not just because since the O.J. Simpson case, but just generally since the trumpeting of DNA as the answer, juries expect elaborate forensic detail. They expect the kind of stuff that they get in television dramas. They want that kind of level of forensic analysis even though it's completely unnecessary, even though it's completely redundant. Police departments are operating under economic constraints, so if they can establish something through a straightforward, cheaper method, they will obviously do that if it's incontrovertible, you know? But then you go to court and the jury does - you're right - expect something much more elaborate.
SIMON: Val McDermid, as someone who's written more than - or almost 30 books of crime fiction, can you tell us how some of what you may have learned doing this nonfiction book might affect your fiction, give you story ideas?
MCDERMID: Certainly. I mean, the thing is that quite a few of my books have ended up as they are because of conversations I've had over the years with forensic scientists. One example would be in latest my book, "The Skeleton Road," the story centers around a skeleton - human remains that were found in an inaccessible pinnacle on a roof of a condemned building in Edinburgh, and one of the things that I found out in the course of researching the forensics book was that there's a certain bone in your skull that, when analyzed, can reveal where your mother was living when she was pregnant with you. (Laughter). I think that's just fantastic.
SIMON: I am deeply skeptical of that.
MCDERMID: It's true, it's true. It's the - the analysis depends on the content of the air and the water in the specific place where your mother - the area where your mother was living when she was pregnant with you because that's the first bone that forms in your body as a part of the skull bone, apparently. Just as we can take a section of your thigh bone and that will give us a longitudinal picture of where you've been living for the last seven years.
SIMON: Wow.
MCDERMID: It's magic, isn't it? It's exactly those wild moments that I love, and there's a case in the book from - we were talking about insects earlier...
SIMON: Yeah.
MCDERMID: ...Where some maggots were found in an empty house. And the entomologist went and analyzed the maggots and found traces of cocaine. So it was fairly clear that whatever the maggots had been feeding on had been human remains. They did further tests, and so they were able to analyze the DNA that was in the mandibles of these maggots and discover who the victim was, even though there was no body and no missing person report, nothing to connect the identity of the dead man to this house. And again, I think that's just a fantastic story.
SIMON: Yeah. Val McDermid. Her new book, "Forensics: What Bugs, Burns, Prints, DNA And More Tell Us About Crime."
Thanks so much for being with us.
MCDERMID: It's been a real pleasure, thank you. Transcript provided by NPR, Copyright NPR.