Turi King: ‘The Knox case shows there was a misunderstanding about what DNA can tell you’

Photograph by Jane Hilton for The Observer

Professor Turi King is the British-Canadian director of the Milner Centre for Evolution at the University of Bath. She is a renowned expert in genetics and DNA testing who played a key role in identifying the remains of Richard III in a Leicester car park. She is the co-presenter of BBC’s DNA Family Secrets and featured in the Channel 4 documentary Hitler’s DNA: Blueprint of a Dictator. Her new book, The Secrets of Our DNA, looks at how genetics has transformed forensic science, medicine, genealogy and wildlife conservation.

What got you interested in biology and specifically the study of DNA?

The turning point for me was sitting in a lecture at Cambridge. I was doing biological anthropology, and Erika Hagelberg was discussing the Romanov case. Tsar Nicholas and his wife, their five kids and some of the extended family members were killed during the Russian Revolution, and their bodies were hidden and not found for decades. Their identities were established by a combination of osteological analysis and genetics. It was Prince Philip who gave a sample of his DNA to be used as a comparator against the Romanov family. And that was it. I was hooked. I knew right then that that’s what I wanted to do.

You led the DNA verification of Richard III. How important was that project scientifically and culturally?

What I loved about it was that it wasn’t just the genetics. There were lots of different strands of evidence – genetics, osteology and radio carbon dating – and it involved people from lots of different areas, all bringing their expertise to make it a wonderful project. It was also the oldest cold case that was solved, identifying somebody 527 years after his death. When I first came to England from Canada, my aunt took me to the Bosworth battlefield because she was interested in Richard III. I knew he was supposed to be buried somewhere in Leicester, so it was a fascinating combination of history, mystery and forensic techniques.

A film with Steve Coogan, The Lost King, was made about the search for Richard III. What did you make of it?

I think one of the things that was missed in the film is that no one person could have done it on their own. Philippa Langley [from the Richard III Society] absolutely got the project off the ground, but didn’t have the expertise to lead it. Another thing the film didn’t capture was all of the women who led various aspects of the science. I’m not worried I wasn’t in the film, but it was two years of work. Nor did all the money come from the Richard III Society. Some of it did for the excavation, but the vast majority came from Leicester University.

Last year you conducted the analysis of Adolf Hitler’s DNA from a blood sample found on the sofa in the Berlin bunker where he killed himself. How difficult was that, and what did you make of the criticism that it was too speculative?

In a similar way to Richard III, you have to examine the provenance of the sample. Then it’s doing a genetic match with a male line relative. But could it be any other male line relative who happened to get into the bunker and bleed on the sofa? Once that’s been settled, you do the whole genome analysis. There were various rumours about his genitalia, and we found he had the genetic variant that is associated with Kallmann syndrome [which is linked to impaired sexual development]. As a geneticist, I’m the first person to tell you the DNA cannot tell us what Hitler’s genitalia looked like, but it’s interesting to find this result because of the historical documentation. His polygenic risk scores placed in him in the top 1% for autism, bipolar and schizophrenia.

There is a famous old song that refers to a shortcoming in Hitler’s genitalia. Is that coincidental or did the songwriters know something?

There were rumours around that he had lost a testicle in the first world war. There’s also a rumour that it wasn’t in the first world war, that it was actually from an altercation with a goat. Then you’ve got the fact that in 1923 he was in Landsberg prison and a doctor examined him. He described a right-sided cryptorchidism [an undescended testicle]. I don’t know if that information would have been available to the people who created the song.

You mention the Chinese scientist He Jiankui in your chapter on modern Frankensteins. He claims to have created the world’s first genetically edited babies. Is that something we’ll see in the future?

Yes, I think we will. The problem with He Jiankui is that he did it for fame and fortune. As ever, it’s not that we should be afraid of what the technologies are and what they can do. What’s important is to take careful steps and have guidelines and the guardrails in place. There has to be a bigger discussion about how we want to use this amazing technology. There’s the potential for relieving suffering, but it has to be done ethically.

You also look at the OJ Simpson trial. The DNA evidence in that case was overwhelming. How did he get off?

What’s interesting is that the defence never said that the DNA evidence was wrong. Instead they went for two different tactics. They said that it was planted and that it was contaminated. That’s the way they poked holes in the prosecution. In some ways it was the very early days of DNA being presented in court, and there was the background of race riots in Los Angeles, questions about the racism of the police, so enough doubt could be sown. DNA has to be taken in context. It’s never something that you just use on its own.

By the same token, how was Amanda Knox, another case you look at, ever prosecuted?

There’s something known as the CSI effect, this idea that DNA is all powerful and it can answer everything. When you go through the Knox case, there was clearly a misunderstanding about what DNA can and cannot tell you. You could say it was a failure of the Italian legal system to understand the limitations of DNA.

Is there a crime novel you’ve read in which you think the writer has depicted the forensic use of DNA accurately?

I get asked a lot by authors, is this possible? And I can tell them, “no it’s not” or “yes it is”. That’s heartening to me because they clearly want to get it right. The truth is I can’t remember thinking, Oh my God, they got that completely right.

The Secrets of Our DNA: How Genetics Has Changed the World by Turi King is published by Doubleday (£22)