With a career that spans investigating murders at Scotland Yard to identifying bodies after global disasters, one of NZ's leading forensic scientists takes us behind the tape of a lifetime of working on crime scenes.

In this empathetic and darkly funny memoir, Thomas Coyle – one of New Zealand's most seasoned forensic investigators – pulls back the police tape and walks us straight into the crime scenes. With sharp detail, he reveals how the tiniest fragment of evidence can expose a suspect, prove a motive or confirm an identity. Sometimes, all at once.

Tom gives Kete a peek into why he wrote this book now, the compartmentalisation necessary to undertake forensic work, and the limitations of new technology in the field.

Kia ora Tom, thank you for chatting to Kete! Your new book, The Dead Speak, is an account of your fascinating career in forensics. Can you tell us what motivated you to write this?

For many years, clients, colleagues, and even students asked me about my career in forensics. They were often intrigued by the work itself and by the stories that inevitably come with decades spent in the field.

The real turning point came when I was appointed a Member of the New Zealand Order of Merit. During the ceremony, I had a brief conversation with Dame Cindy Kiro, and I mentioned that I had thought about writing a book one day. Without hesitation, she said, “You must — and I would read it.”

That moment stayed with me. And I mentioned it to my family and friends, and for the first time it felt like the right time to do it — and to do it properly.

On the back cover, it says the book is ‘not for the faint-hearted’, and it really isn’t. Stomach-churning moments are obviously something that you have to cope with, but the emotional impact must be harder still?

In forensic work you learn, out of necessity, to compartmentalize — to switch off the emotional side while you’re doing the job. That isn’t about being cold or detached; it’s about being able to function professionally, make clear decisions, and do the work properly for the people who depend on you.

That said, it’s not always easy. Some of the scenes I’ve attended stay with you long after the work is done, and no amount of experience makes every situation manageable. Coping comes from recognizing that and not pretending otherwise.

I’ve also been incredibly fortunate to have a very strong family support group, especially my wife, who is my rock. Being able to switch off when I come home, talk when I need to, and have that grounding support makes all the difference.

The Police also have a very strong support network in place. There is access to professional support, including the option to speak with a psychologist who is completely independent from your colleagues and your family. Having that space to talk openly, without judgement or connection to the work environment, is an important part of managing the long-term emotional impact of this kind of work.

Who did you write this book for? Was any of it for the ‘CSI’ watcher who needs re-educating?

I wrote this book for anyone who has an interest in forensic science, whether it is those that are avid viewers to dramatized crime shows or those that are genuinely curious about forensic science.

If it helps re-educate the occasional CSI watcher, then that’s no bad thing. Popular television has created a very polished, fast-paced version of forensics that doesn’t reflect reality. Real forensic work is slower, methodical, and completed with integrity.

DNA testing and advancement in technology has made significant impact on forensic analysis. How do you view this advancing further in the future?

Advances in DNA testing and forensic technology have already had a major impact, and that progress will certainly continue. Faster results, smaller sample sizes, and improved analysis have changed what’s possible in many investigations.

That said, there are clear limitations. As technology, particularly with the advancement of AI, becomes more sensitive, it can also become less practical for use in court. We’re already seeing this with technologies such as DNA 'wands,' where a device can be passed through a crime scene and generate DNA profiles of people who may have been present.

The issue is context. DNA can be introduced entirely innocently — through an open window, air movement, or even an air-conditioning system. Highly sensitive tools may detect cells from people who have no connection to the event at all, which creates serious evidential and ethical concerns.

The future of forensic science isn’t just about more advanced technology, but about balance — using new tools responsibly, understanding their limitations, and ensuring that evidence remains reliable, explainable, and suitable for court proceedings.

Do you have plans for any more books? I’m sure you must have more stories from your career to tell.

I certainly have many more stories I could share, but for now I feel the ones described within the pages of this book are enough. They say what I wanted to say at this point in my life and career, and I was very conscious of knowing where to draw the line.

That said, I do have a burning ambition to write a crime novel. I’m currently in the early stages of formulating a detailed framework — developing the characters, shaping the storyline, and working through how it all fits together. It will be fictional, but informed by experience, and I already have a wonderful twist in mind.

Whether that becomes the next book remains to be seen, but the idea is very much there and quietly taking shape.

The Dead Speak: My Life in Forensics by Thomas Coyle is in all good bookstores now.