Having just finished a national theatre tour I can vouch for the fact that being on stage is both exhilarating and exposing.

There’s an electricity that comes from performing in front of an audience because they bring with them enthusiasm and an almost intoxicating, infectious energy. But then again there’s always a fear that at any given moment you might forget your lines and you will be left alone, bereft and exposed, or that you’ll become derailed by something unexpected happening – such as when someone appeared to faint at my Glasgow performance.

There is often an element of surprise. One question, asked by a member of the public, who had paid hard-earned cash to come and hear me speak, quickly became my favourite, perhaps because it was so unexpected and silly.

Touring is exposing, as I still find it hard to accept that people actually wanted to pay to listen to me talk about my life with murderers and hear what I had to say more generally about the phenomenon of murder.

I had a script which I had written for the first half of the evening but in the second half I answered audience questions. That was my favourite part – not only was there no pressure to remember my lines, but it also allowed me to understand what it was that people really wanted to know about murder, or some specific case that had captured their attention and continued to intrigue them.

There were interesting regional variations in all of this so that, for example, Luke Mitchell’s murder conviction cropped up in Scotland but was never mentioned south of the Border, although the fate of Madeleine McCann generated questions both sides of the Border. Charles Bronson and his suitability for parole was also a regular question that got posed more nationally, although only the English seemed to be intrigued by the murders of Megan and Lin Russell.

More generally there were five common topics that cropped up time after time and, even if the specific question about these topics varied, what most people wanted to discuss was whether murderers were born or made; should we bring back capital punishment; am I ever scared when I meet a murderer; do the TV programmes that I present lead to justice for victims; and how can someone commit the “perfect” murder?

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This last question, which I hope was always posed as a bit of fun, allowed me to talk about the need to self-censor in my work. I’m simply not going to explain how to kill someone in such a way that you might evade capture and nor was I going to tell “war stories” about encountering this or that violent offender or serial killer almost as if that was a form of entertainment in itself. No doubt there are some speakers who want to dwell on this type of encounter, but that didn’t seem to me to be a very responsible way of engaging a public audience and challenging their perceptions about murder and murderers.

So, I explained, yes, I have been scared but often that’s when I’ve failed to prepare for a meeting properly, or rushed into a situation without thinking through the consequences. I should never have met with a hitman in a café in Manchester, for example, without considering my own safety. Throughout the tour I explained that I am against capital punishment and offered, as I have done many times before, the answer to the nature vs nurture question – it is neither one nor the other, but a messy combination of the two that is unique to that individual.

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The hardest question to answer related to the impact that programmes that I present or co-present have had on a live, or cold case. This was challenging territory and I usually started my answer by explaining that the broadcast rules in this country are different to those that exist in North America and Australia and that there are also different legal protocols and guidelines covering podcasts, as opposed to documentaries.

Frankly, it still amazes me how some podcasts are able to name people that they suspect of some awful crime without being taken off air or sued. Nor are our police, I suggested, eager to work with a TV company – that might be too exposing of them – and my many pleas to get the Thames Valley Police, or the Metropolitan Police, for example, to work with us on the last series of Channel 4’s In the Footsteps of Killers fell on deaf ears.

In that series, we knew “beyond reasonable doubt” the identities of the killers in four of the six episodes but were prevented from naming them for all the legal reasons that I have described. Even so, we handed over all of our research to the relevant police force at the end of the series and I still hope that it might be of assistance. To that end, I was delighted to see earlier this month that Sussex Police are going to be following “new lines of enquiry” in the case of Vishal Mehrotra – a case that we featured in the series and where I believe we really opened up new territory.

I also explained how the families of the murder victims that we feature are usually delighted that we are trying to do something, because they often feel that they have been ignored or disregarded. In fact, it’s often the family themselves who have made contact with the production company and we have never featured a murder when a victim’s relatives don’t want us to film their case. Justice – catching the perpetrator – is of course what we are all seeking, but sometimes simply getting publicity for their murdered loved-one gives them another form of closure.

And my favourite question? It came from an audience member in Canterbury who asked “Professor Wilson, please could you advise what is the best way to cook a whole halibut?” Crime and punishment I can do, but cooking?

Emeritus Professor David Wilson is a leading criminologist