How witness interviewing techniques influence evidence
In the case of major incidents such as terrorism, other crimes or an accident, emergency services rush to respond and save lives. But in this episode of Life Solved, we find out how the stress and pace of high-risk scenarios can influence the behaviour and memories of witnesses to such incidents.
Professor Becky Milne and her colleagues at the University of Portsmouth know this kind of witness experience, and the way in which interviews are conducted, can make a big difference to the evidence gathered. That’s essential in preventing further crime and seeking justice.
Becky applies her innovative research working with emergency responders, from paramedics to police investigators, to call-handling in control rooms. She explains how the important psychological insights gathered from incidents such as the 2017 London Bridge Terror Attack have led her to develop a more effective evidence-gathering system, hand in hand with forces.
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Professor Milne looked at how police were gathering information from witnesses and victims of crime and quickly noticed that the way in which questions were asked influenced the kind of answer given. Sometimes, poor questioning could lead to incomplete or inaccurate information – something that can make the difference between achieving justice and not, or even life or death.
In addition, something called ‘evidence contamination’ was happening in pressured scenarios. Even police and emergency services could find their memories or a situation were impacted by stress, so Professor Milne began to develop new techniques for getting the best information. She says this is based on our understanding of how different parts of the brain store information:
With a one off event, like a terror attack, this is what we call episodic memory. And that type of memory is stored all over the brain. And so when we say, tell me what happened, people have to piece it together like a jigsaw puzzle.
Interviewing for accuracy
Training emergency responders and police officers in her new approach, Professor Milne was able to ensure services were equipped to process a lot of information accurately. She worked in fire brigade control rooms where call handlers have to quickly understand a situation and get the right team deployed.
The London Bridge Terror Attack of June 2017 was to put Professor Milne’s approaches to the test. Emergency responders, police officers and the public had all experienced trauma, and it was important to minimise the impact of this on the information gathered. This required a highly specialised skillset:
It was a very raw trauma, almost in the wrong place, wrong time. It wasn't personal in a way. But interesting to experience that different type of trauma. And we've learnt a lot.
This tragic event provided a deeper insight into where tools could better be developed. Professor Milne was able to propose a tiered approach to interviewing officer’s specialisms, with the most highly-trained individuals assigned to witnesses with high levels of trauma or vulnerability, and overseeing external experts.
She claims there is one key asset that makes a top tier interviewer capable of carrying out this complex information-gathering:
Emotional intelligence is understanding who you are and how you impact on this interaction. You might need to change your behaviour across that interview. I think it's understanding what you're good at and what you're not so good at within that environment, and then learning to curb it.
Interviewers and communicators with high emotional intelligence seemed to be able to adapt their own behaviour to that of the interviewee to avoid interrupting them, or to encourage them to talk.
Professor Milne and the team are now hoping to extend this approach into international scenarios so that justice can be carried out for the world’s most vulnerable, from refugees to prisoners and witnesses of human rights infractions.
John Worsey: You're listening to Life Solved from the University of Portsmouth, where research is taking place to change our world for the better. I'm John Worsey and in this series, we're meeting some very clever people and understanding how they're making a difference in your life and mine. Today, we meet Professor Becky Milne, Professor of Forensic Psychology.
Becky Milne: As my good old mum said, I get paid to talk about talking. I think I found my niche in life.
John Worsey: The way police behave during and in the wake of emergency incidents, whether a terror attack, crime, accident or otherwise is critical. But few of us might have thought about how this behaviour can have an impact on the evidence that's gathered from witnesses.
Becky Milne: Human beings have only limited cognitive resources. Like a computer, we only have so much processing power.
John Worsey: And it's this evidence that can be vital in identifying a perpetrator, exploring what happened or understanding a chain of events.
Becky Milne: So at a scene, if you've got five witnesses, we will get five different versions of the event because they will all be filtering that information.
John Worsey: Today, Becky tells us how and why her team's research is revolutionising communication during traumatic incidents by working hand in hand with responders. We'll also find out more about their crucial involvements in incidents such as the London Bridge attack of 2017.
John Worsey: Becky and her team research communication skills for investigative interviewers, and they recommend the most effective techniques in that field.
Becky Milne: The research that I have been doing for over 25 years and now with a large team of people, primarily is looking at how communication can help in gathering accurate and reliable and fulsome information. Now, normally we look at it within the criminal justice arena. People are making decisions, so whether you've got police officers, fire officers, paramedics, they're all making decisions, often dynamic situations, and they're making decisions very quickly. Now, decisions are only as good as the information you feed into it, and information is only as good as the questions you ask. So poor questions result in poor information, which results in poor decisions. So we have been looking at how best to gather information at various parts of the justice system, from frontline communication to call handling through to formal interviews so that we can ensure that the information gained by practitioners is good information, reliable information, so they can then make informed decisions. So I first started looking at how police gather information primarily from witnesses and victims of crime, and especially those who are especially vulnerable children and people with learning disabilities.
Becky Milne: The work really is focused on the police for the majority of my career, but I have been working more recently on terror attacks. So for the last sort of eight years, the UK now has seen a resurgence really of terror attacks, more recent terror attacks. And we had a succession of them. And so we started and I started advising the police on how best to gather information, which then started us looking at not just the police, we've also started looking at how the fire service gather information, especially with the call handling side of the business. And also we just started working with paramedics.
John Worsey: The team work with fire brigades to help make sure their control rooms are as effective as possible.
Becky Milne: We've been working with London fire within the control room about how to assimilate the information gained from a call and the best types of questions, again, to ask to gather the most accurate information so they can make informed decisions and then pass it on to the wagons who are going to the-- to the incident. We've also been doing this similar work with Hampshire Fire and West Midlands Fire Services. So it's not just London. It's going across the country looking at that control room. I mean, if you start thinking about control room, it is a very difficult scenario. Human beings have only limited cognitive resources. We-- we all have, like a computer, we only have so much processing power. A majority of us can't multitask. Now, think about a call handler, the things they have to do. You know, they have to field a call. They have to think about the next question. They have to type the response. They have to make a decision, do I send someone now or later? They have to deal with people who are often in jeopardy at the end of the phone. And now, you know, with the wonder of technology, people can send in in some situations footage of the scene and they're having to process and assimilate all that. I mean, that is an amazing job that they are doing. What we're expecting that brain to do is really quite something. And so we've been working with the-- the fire service to look at how we can help them, to enable them to process this multitude of information, to make really good informed decisions using good questioning. And so it's often the voice tone. The manner. You can't get that off of a transcript. So we tend to do most of our analysis on actual recordings and even better will be a visual recording.
John Worsey: Evidence contamination can happen when the subjective experience of an event and how it's mentally processed can change the subject's recollection. And to state the obvious, police are human too, and they're not immune to the same forces. Becky explained how she can assist with accurate information gathering and retention of information in traumatic situations.
Becky Milne: One thing is you have different types of memory and episodic memory, this one-off event, is constructed. Also, memory is very easily contaminated, and that's really important. I always liken memory to snow, you know, you wake up in the morning, got a field of white snow. The problem with snow is when you start walking on it, you contaminate it. It's the same as the human brain. And so memory can be contaminated all the way through. So whenever I work with any witness, victim or suspect, I look at the contamination timeline of each individual.
Becky Milne: So obviously at the scene itself, you've got potential contamination at the scene. You might have something called weapon focus effect. So at the scene, if there's a weapon, people will be drawn to the weapon, perhaps and away from other aspects of the event. Only information which is taken in at the scene will be there for later retrieval. And perception at a scene is, you know, it's like pouring water from a jug into a vase. If we pour it too far, some of it will overflow. Because we can't take everything in, especially in a dynamic situation, you know, all the sounds, smells, tastes, you know, our feelings. Our brain will automatically filter, and this is the perceptual processes. And only what it's decided to take on board will be stored potentially for later retrieval. And so at a scene, if you've got five witnesses, we will get five different versions of the event because they will all be filtering that information. So that's sort of one thing we need to be mindful of. They will all give different aspects, again, of who there are. We call it a top-down process. So we know police officers tend to focus on faces. Teenagers might focus on accessories. You know, if there's a weapon, people focus on weapons. So that's the first sort of point of sort of contamination is how the brain is managing that mass of information and going at a, especially a dynamic scene.
Becky Milne: If you've got five witnesses all together and one witness on their own. Of course, the five witnesses are there talking. So the conformity effect is massive, so people will start talking and forgetting the source of the information, who said what? So there's not much we can do as a criminal justice process because this is prior to any intervention. But we need to be mindful of who is at the scene, where-- you know, where they were and what was really going on at the scene to understand the reliability of the information there. So that's the scene itself is sort of first point of contamination.
Becky Milne: Then, of course, the second point is normally one of those people will ring the emergency services. As I've already mentioned, the emergency services will have a call handling system. So how well that information is extracted, communicated with and then recorded will impact. Now, this is what we call preventable error. So from now on, what we're looking at is where we can create processes and practises to prevent as much err possible. Nothing we can do at the scene prior to any sort of emergency services turning up. But now we can. So that's why we've been looking at the call handling system, then the first responders. This day and age, most responders wear some form of camera, a body-worn camera. So there's been a whole lot of research looking at communication at the front line. One of my PhD students, someone called Gary Doulton, who also works at university as a lecturer. He's been looking at that front line communication. And again, if police officers aren't trained or any emergency services at that, they'll be using their everyday conversation. So there needs to be some form of training at the front line to make sure that we use the right questions to gather the right information.
Becky Milne: Then we got the formal questioning, which is where my work really started all those years ago. And you go through the contamination timeline. Then you've got the legal practitioner coming into the equation, the Crown Prosecution Service. Then obviously you've got the court process itself. So this is the contamination timeline and memory can be contaminated all the way through until we make that decision if it gets to a court of law of guilt or innocence. I will see this memory as such a fragile thing in someone's hand. And unfortunately, a lot of time it's, you know, by the time we hit court to make those decisions, there could be problems.
John Worsey: In June 2017, terrorists drove a vehicle into pedestrians on London Bridge and then attacked people in the area armed with knives. The three perpetrators and eight victims died with many more injured. Becky assisted the police in how to interview witnesses, many of whom had been traumatised by events.
Becky Milne: When the attack broke, British Transport Police came to me to ask my advice on how best to deal with the multitude of victims. Now, primarily we were dealing with police witnesses, with British transport police, and we had a large number of police witnesses on London Bridge. I helped create with them, so it was definitely a partnership, a triage type of system. So where those people who were near to the attacker and attackers, not only based on their proximity and the amount of information that we were believing they could share of the incident, but also on their trauma levels. So we have to make sure the people who are most trained dealing with the most traumatic. Then we categorise CAT B and C. So that was the first thing was helping with that triaging process.
Becky Milne: The second thing was then I helped create the strategy of how best to interview those CAT A witnesses. Dealing with trauma, we also got a trauma expert from the military. I've dealt with trauma a lot over the years, especially when dealing with children who have been abused. And it's quite a different type of trauma. With children who've been abused, it's more of a betrayal trauma. They've been betrayed by someone close to them. With a terror attack, it was quite different. It was a very raw trauma, almost wrong place, wrong time. It wasn't personal in a way. It was an interesting to experience that different type of trauma. And we've learnt a lot. And so I helped with the advice of how best to deal with the people, what types of questioning strategies. And also I was at the end of the phone when those interviews were being conducted. I helped actually train the individuals who did the specialist interviews originally. The result was a collaborative piece of work, which was called WISCI. Witness Interview Strategies for Critical Incidents, which is a framework for, if there is another one, of how to manage mass witnesses in such situations. It's a starter for 10, because every incident is different, of course, so it has to be amended. You can't have a bespoke this is exactly what we do, but at least we've got a sort of a framework now, a starter for 10 from what we have all learnt.
John Worsey: A major part of this advocacy is training police officers in an effective way. Becky told us how she's developing new approaches all the time.
Becky Milne: If we use our everyday conversation of police officers you use everyday conversation, that doesn't promote people giving lots of accurate, reliable and detailed information. So research started looking into two areas. The first was how do we get police officers and other communicators in this sort of sphere to talk differently and how long it takes to teach them to talk differently using such as open questions, tell me everything, explaining that detail is required in this sort of scenario. So that was the one lot of research. The other lot of research was creating techniques that a police officer could use with the general public, which would get the general public to understand that detail is OK. It's OK to dominate a conversation with the police officer who is in authority. In fact, the police officer wasn't there, they don't know what happened. It's the witness victim who has that information. And also, if you look at the television, you know, the media representation of police interviewing is not the best. So we had to create techniques, myself in the team, but also lots of researchers around the world, that police could use to enable the public to do just that, to give you accurate and reliable information.
Becky Milne: I have been looking at it in two ways, one is the psychology of communication, such as communication rules, but the other is a memory, a memory theorist. So understanding how the brain works and how the different types of memory relate to the different types of incidents that we might be interviewing about. So, for example, with a one-off event, like a terror attack, that's a one-off event, this is what we call episodic memory. It's a very rich memory in someone's life. And that type of memory is stored all over the brain. And so when we say, tell me what happened, people have to piece it together like a jigsaw puzzle. And so we say it's constructed. Now, that type of memory, we need what we call a free-flowing narration and the type of incidents that we're working with, people are often traumatised. So we're also looking at the trauma impact on the reporting and on the memory and the brain process.
Becky Milne: So what we know from work that we've done in Norway with a colleague over there, one thing that we learnt, which we've imparted straight into practise in the UK, is for someone who is traumatised, who needs to give us information which might be quite difficult to talk about, the best way, the most palatable way to do that is if they are in control of the flow of the information. So to allow that free-flowing narrative so they can stop and start when they want, they are in control of the pace of the flow. And that was a really important learning. So we have put that into police training, but also into our advice. Straight into how police officers interview victims and witnesses to such traumatic incidents in the UK, these critical incidents to allow that free-flowing narrative.
Becky Milne: I've got currently, I'm working with twenty-one PhD students. I've also had twenty-one PhD students who have worked with me in the past. And a lot of us is creating coding systems. So one of our coding systems is 167 behaviours that we look at across a police witness interview. In Britain, we are the first country to really start looking at what goes on in the police interview room. Prior to 1992 in this country, there was no national training framework for police interviewing. People thought that you learnt on the job. You learnt from more experienced colleagues, and we all realise quite soon that experience doesn't equal competence in interviewing. And we created what we call a tiered approach to interview training. We drip-fed interviewing skills across a police officer's career span as and when they were able and asking when they needed it for the more complicated cases.
John Worsey: But above all of this training, Becky and her team have focussed in on one particular area in interviewing – emotional intelligence.
Becky Milne: So the senior investigating officer of a case, obviously, has a multitude of tasks to do themselves. And one of those tasks is what information gleaned from an interview.
Becky Milne: So now we have this interview strategist, this tier five we called interview manager, who will help look at the strategies, they will pick the best interviewers. They will take that job away from the senior investigating officer so he or she can deal with managing the whole enquiry. And the tier five will manage the interview process, maybe bring experts in, trauma experts, people like myself, and they will provide a framework. And they act sort of as a go-between-- between the actual interviewer to get on and do the interview, the specialist interview, as well as the senior officer. And they manage that whole process.
Becky Milne: And then it really begs the question, doesn't it, of these advanced interviewers, these specialists, this X-Factor. What is it? Can we bottle it, you know? And we have started looking at what this X-Factor is. We think it could be something called emotional intelligence, this understanding who you are and how you impact on this interaction. But it's not definite. And so that is where our research will head is looking at this X-Factor. What makes someone such a wonderful communicator? I was training in London last week for a whole week and you could see who the naturals were. As a psychologist, it's quite interesting, quite fascinating to try and work out what behaviour or skill or personality variable enables them to do that. Because as an interviewer, you would think someone is an extrovert. You know, you've got to tone your behaviour completely down because otherwise, you're very interruptive of that free narrative process. So, in fact, you need to change your behaviour across that interview, too. And I think it's understanding what you're good and what you're not so good at within that environment, part of that emotional intelligence and then learning to kerb it.
John Worsey: And these skills are particularly important in cases of vulnerable people.
Becky Milne: It's always been a thread with all my work, is whether people are vulnerable because of age, young and old, whether they're vulnerable because they have a learning disability or vulnerable because of the impact of the event itself, such as trauma. That what we know with vulnerability, that we just have to be even more careful within that interview room to make sure that we don't put words into people's mouths, that we allow them more time. And one key thing for dealing with and communicating with people who are vulnerable is planning and preparation and assessment. You know, so it takes time for that process to make sure that when we go and interview someone properly that we have really thought about the best ways to do that. And so planning and preparation and assessment is key when dealing with vulnerable groups, because all the things I've said already with a regular adult goes tenfold, almost with someone who is vulnerable. So you just have to think about what you do and say and be more measured. You know, you have less time, maybe less concentration span. If someone's had a physical injury, you know, when they've gone through surgery, you might just have less time because they're just feeling uncomfortable physically. So even something as basic as that.
John Worsey: Thanks for listening to this episode of Life Solved from the University of Portsmouth. You can find out more about the work of Becky and her team, as well as our other projects by going online to port.ac.uk/research.
John Worsey: If you want to share your thoughts on this programme, you can do so on social media using the hashtag Life Solved. Next time we find out how virtual reality simulations are outsmarting burglars.
Claire Nee: Actually getting to re-enact it using the virtual environment makes them disclose so much more because they're actually doing it. So their schemas are popping out of their long term memory while they're doing it, they're not hindered by trying to remember what happened.
John Worsey: Make sure you subscribe in your podcast app to get every episode of Life Solved automatically. And please do tell us what you think with a review and rating if you get a moment. Thanks for listening.