Val McDermid and Lin Anderson arrived on stage alone, joking that it had been decided that no one could moderate them. They briskly launch into a discussion on the development of forensics. McDermid’s first book was published in 1987, just a year after DNA had first been used in solving a case. At the time forensics largely consisted of fingerprints and trace evidence, often using techniques that have since advanced beyond recognition or are now dismissed as unreliable. Originally you needed a bloodstain the size of a 50p coin to get a DNA sample but now they can extract it from samples a fraction of the size of a grain of salt. This leads to the problem of not just getting evidence of a crime but completely irrelevant evidence as well. If you swab a murder victim the DNA you find will include that from anyone they’d hugged. If you swab a fence post near the scene you will get DNA from everyone who has touched it, including the post maker. The onward march of forensic science has radically changed crime scene investigation and crime fiction has had to change in tandem.
Anderson explains that when she was first starting out she’d had a student who had gone on to study forensic science. At the time she wasn’t entirely sure what that involved, as this was the days before CSI, but when she was wondering how to place her character at a crime scene she remembered this girl and decided to make the character a forensic scientist. She adds that an early interest in computer science was helpful, as developments in forensics and computer science have often gone hand in hand. McDermid agrees and points out that her early interest in computers and programming was helpful when trying to understand forensic experts who started explaining using statistics. She once heard about an algorithm that was used for geographic profiling to catch criminals who moved around to commit crimes. She put it in her book, hoping that it was something that actually worked and was then pleased to see the original expert on the American news a few years later explaining how it was helping an ongoing case.
Anderson then says, “Shall we talk about maggots?” She was at one point involved in a dream panel of forensic experts, one of whom loves maggots and had her excited about them by the end. McDermid visited this expert’s office in the Natural History Museum when researching her book on forensics. He had pointed out some innocuous looking suitcases in the corner and informed her that they’d had pigs’ heads in them at one point. When she asked why, he explained that they needed to find out which of the insect species involved in the sequential decomposition process could lay eggs through the zip. Maggots can be useful in a variety of ways forensically speaking. They don’t bite the flesh they eat but tear at it, meaning that fragments get left behind in their teeth. DNA can be extracted from those fragments and used in identification. In one case police in Scotland found a maggot mass in a flat that looked too big to belong to a pigeon or another pest. The maggots were sent for analysis and the first finding was that they had been high on cocaine. This led to a brief and hilarious tangent about Glasgow filling up with fast flying coke filled pigeons. Once the DNA from between the teeth of the maggots had been analysed it came back as a match to a drug dealer from Liverpool, who hadn’t even been reported missing at that point.
Discussion progresses to the people you meet when doing research and the stories they tell. Anderson once asked an expert she knew about what would happen in a fire in a skip containing a body. She initially found out that the parts of the body covered by cardboard would be protected while the head would explode. Then she discovered that the expert she had asked had once dealt with a similar case. She went on to explain to Anderson that the police always forget that women can’t just go and piss in the street nearby and they also always forget that the forensic team are going to get hungry. She was standing scraping burnt exploded brains for evidence collection when a police officer came to ask if she needed anything, receiving an odd look when she asked for a smoked sausage supper. McDermid agrees that it’s fascinating to meet experts and see what they do and the variety of effects it can have on them.
When they ask for the lights up an audience member asks if they’ve ever made mistakes with the forensics. McDermid laughs that she’s made many mistakes in life but few in her books. Anderson recalls a story Ian Rankin told her about putting twelve people in a jury, forgetting that he’d known that number from American television and the number in Scotland was fourteen. “Fifteen” McDermid corrects and they both have to pause to laugh before agreeing that it’s always the things you think you know that catch you out. There are also issues with English and American publishers who don’t know the differences in the Scottish justice system or don’t understand the ‘Scottishisms’ that slip into their work.
At one point McDermid explains that she lives in the top flat of a stair with lovely neighbours who are absolutely thrilled to live in the same stair as an author. Whenever a new book of hers comes out one of the neighbours scans the cover, frames it, and hangs it up in the stair. McDermid’s partner is an academic and has also published books. Recently the neighbour came to the door explaining that she was horribly embarrassed as she had just realised she had been neglecting the second author in their stair. She asked if McDermid had a copy of her partner’s book and now their stair is filled with crime fiction book covers and one cover titled ‘Geographies of Post Colonialism’.