Vern Pierson

A man named Ricky Davis was imprisoned for a 1985 murder in El Dorado County, California. He spent years in prison until the Innocence Project took on his case. As the District Attorney in El Dorado County, it was you that the Innocence Project had to convince that the case needed to be re-examined. This led to Davis’s exoneration in 2020 after spending 12 years in prison for a crime he didn’t commit. I am sure you often hear claims of innocence from those prosecuted in your county. Why was Ricky Davis’s case any different?

I’ve always kind of had a love/hate relationship with the Innocence Project. They have approached me on other cases, and I look at them and there’s so much overwhelming evidence of guilt, yet they’re suggesting that we retest a cigarette butt found in an ashtray. It’s not going to change the outcome of the case. When they approached me (about the Davis case), I kind of felt the same way, but they had a transcript of an interview with Ricky Davis’s girlfriend. Just flipping through a couple pages of the transcript it caught my eye that there was a section where she changed her story when the detective corrected her. That just struck me her not actually telling the story about something she remembered. It sounded much more like she was merely telling the detective what she thought they wanted to hear. That concern, and the willingness on the part of the Sacramento County DA to retest a bunch of the forensic evidence was really what happened. Over a period of time we tested forensic evidence, put different pieces together, and then ultimately used forensic investigative genetic genealogy to identify who the real killer was.

In 2024, Netflix’s highest-rated docuseries, “American Nightmare”, detailed the 2015 kidnapping of Denise Huskins and her husband Aaron Quinn. The case gained worldwide notoriety because although the couple survived, they were publicly defamed by local police and the FBI, who claimed they made the whole thing up. Perhaps investigators felt they could detect deception like the investigators featured in another infamous Netflix documentary called Making a Murderer, where flawed interrogation techniques were implicated in that case’s miscarriage of justice. What role do these types of documentaries play in changing the interrogation practices of investigators?

We’re seeing the power of the narrative in that if a person can watch a documentary, and even if the documentary is not completely accurate, but closely accurate, they can feel as though they understand the circumstances. People watched those documentaries, and they felt as though they were experiencing the events. They were well done and well produced in that regard. And when they felt it, they were left with the conclusion that they didn’t like what they were feeling, and they didn’t like what they were seeing. They didn’t like the intentional use of deception, and the intentional use of pseudoscience to say this person is not behaving the I have been trained that a victim of crime should behave. They didn’t like seeing that once the detective had concluded the person wasn’t being truthful, the detectives in some cases used things like minimization and maximization, or a false choice which are all flawed techniques. In these cases, the detectives were doing what they were trained to do but the training was flawed in that it incorporates pseudoscience and the use of deception in it. We all have to realize that our jurors that sit in and evaluate these cases, evaluate the way we investigate and prosecute cases, and they don’t like it. Just recently I had a detective tell me, “Well, it’s worked really well for me doing this type of (conventional interrogation) approach.”  I replied, “OK, it may have worked for you. The problem is the next time you use one of these techniques and it goes to trial, you run the risk of a juror refusing to vote to convict the person because they simply do not like what they saw in one of these documentaries and then when they heard about it in the case in front of them, they were angered by it.

I know from my own experience that there’s a handful of false confession cases that in addition to the ones documented in the Innocence Project’s database, the person spent a lot of time in prison for something they didn’t do. False confessions are one problem, but perhaps the bigger thing for me is what is in “The American Nightmare” case that you referred to, the officers in that case felt as though Aaron (one of the victims) was not conducting himself the way someone who had suffered a home invasion and had his girlfriend kidnapped would act. Then they felt Denise (the other victim) was not behaving the way she should have. They reached those conclusions based upon their training, which included pseudoscience and deception detection, and they concluded that the victims were lying. The detectives increasingly ignored evidence to the contrary and instead acted out of confirmation bias. We now know, because we re-opened that case, that two weeks after Denise was kidnapped, Mueller (the kidnapper) did a home invasion robbery in the city of San Ramon (CA). We also know that a month and a half later he did another home invasion in the city of Dublin (CA). We also know that he previously kidnapped and sexually assaulted a woman when he was much younger, when he was only 16 or 17 years old at the time, and we’ve identified that case and that victim. Mueller has now pled guilty to two additional home invasions in Santa Clara County (CA). So, it’s not just Aaron and Denise’s case that was the problem, it was the other types of crime that were permitted to continue or to occur because the detectives got it wrong based upon bad training.

You have become a vocal advocate for reform in the way law enforcement officers are trained to conduct investigative interviews. While the industry as a whole has adopted new technology such as drones, sophisticated crime scene mapping with lasers, and even AI-assisted report writing, why do so many law enforcement investigators seem reluctant to change the way they conduct interviews?

Frankly, there are some training vendors who are very good at marketing nonsense. I have seen advertisements to detectives that say how to build rapport and still get the confession! The truth is science-based interviewing is not something flashy. It’s not the “here’s how to detect lies every time” type of training that is out there. It’s more about being patient and doing the hard work that leads to being more successful in your interviews.

I’ve been working in law enforcement as a prosecutor for over 30 years. I have a very high opinion of the people who are in  law enforcement. They’re incredibly altruistic. They want to serve the communities where they live and hold people accountable for their actions. That’s why they get into this business! When somebody markets to them that they can attend a training class where they’ll learn a technique or methodology to tell when someone’s lying or how to get someone to confess to you, it’s very appealing for the officers and we have to understand and appreciate that. The officers are trying to hold people accountable and trying to do the best that they can. The problem is that either the people that are selling that type of stuff don’t realize what they’re selling doesn’t actually work, or they just don’t care.

The so-called “Reid Technique” is often implicated in causing false confessions, but is it just one private training firm that was the issue or are their other problematic training techniques being offered to law enforcement officers?

The Reid Technique was an evolution in the 50s and 60s, away from physical force, or what was known as the “third degree interview” type of interrogation style. The truth of it is that Ried has trained so many detectives throughout the United States that other training providers have taken a lot of what Reid did, and they’ve modified it and are now calling it something else. The best way I can describe it is its derivative of Reid. It’s based upon some of Reid’s core principles but they’re calling it something different. But the notion that you can use someone’s behavior to detect whether or not they’re telling you the truth is false; that rape victims or kidnapped victims or home invasion victims should behave a particular way is false. There are some premises that are built within these training courses that are just false, and I would like to see all of the private presenters providing this training move away from that type of stuff and go to a methodology that is based in science.

Can you talk about the training that you and your colleagues have developed as well as the advocacy work you have been doing to mandate such training across the state of California?

10 or 15 years ago, I really wouldn’t have believed that somebody would confess to a crime, particularly a serious crime, that they had nothing to do with. Over time I found that that was wrong and that they in fact do. I’ve also found that there are approaches to interviewing that are more effective than others. Because of this experience, I’ve developed a good working relationship with organizations like the HIG, the High Value Detainee Interrogation Group. What the HIG did was that they needed to develop the most effective way of interviewing people in their realm, which is intelligence gathering. The HIG’s methods were based on the FBI, the CIA, and the Department of Defense. They hired researchers like Lawrence and Emily Allison and asked them to watch thousands of interviews of actual rapists, terrorists, sex offenders, and then to code them to try to determine what behaviors that the investigator was engaging in led to more yield of information. The yield is fact-based information coming from the subject. So, they looked for behaviors that the investigator would engage in that produced more and less yield. They then pondered if they could develop an approach to interviewing that is built on doing more good stuff and less bad stuff. Out of that process came the ORBIT model, which is a rapport based interviewing methodology or approach. What they found was adaptive behavior on the part of the interviewer produced more information. Adaptive behavior isn’t faking, it’s not pretending to be the person’s friend, it’s not pretending to care about them. It’s establishing some type of warmth or human connection with the person. In other words, recognizing who the interviewee is as a human. In our training we say that warmth and competence are two ingredients that can guide the way the interview goes. But if you use maladaptive behaviors like using deception, and pretending to be their friend when you’re not, those behaviors produce less information and less yield. So, with the HIG’s help and with help from California POST, we looked at how the HIG trained their people and whether we could modify it to make it applicable to local law enforcement. Our methodology isn’t focused on gathering intelligence but rather on solving crimes, be they murder, sexual assault, etc. In essence, the training that we’re providing now is a is a pared down version of the training that the HIG provides to their interrogators, men and woman who have interviewed some of the highest value detainees that come into custody. The training relies upon the ORBIT model among others, and not only does it not produce false confessions in the same way some other techniques do, but more importantly it is a more effective way of getting fact-based information from the people that we interview.

Principled policing, procedural justice, and police legitimacy are all buzz words often touted by police leadership. Can a police chief rightfully claim that his or her agency practices principled policing if their officers and detectives are still being trained to use guilt-presumptive and coercive interrogation techniques?

Well, I unfortunately think some sheriffs and chiefs of police may not know exactly how their people are being trained and what’s actually happening in the interview room. If we go back to the fundamental principles of Sir Robert Peel, the father of modern policing, he said that the police are the community, and the community are the police, so we want to train officers to be part of that. I think there is an inherent ethical problem that occurs when we use deception in the interview room. We all accept that to catch criminals, sometimes we have to operate in undercover capacity and use deception, but that is different than what should occur in an interview room. We need to ask ourselves, is it inherently wrong to train people to lie in the interview room? I believe it is. One thing I would encourage chiefs and sheriffs to look into is the training that’s being provided to their people. For example, recently a detective was being cross-examined about the interrogation training he had received. The attorney introduced the training provider’s manual in court. In the manual, it says that the training provider’s policy was to not use deception. Yet 30 pages into the manual, there are page after page on how to use minimization, maximization, and other techniques with direction that expressly states the themes that the interviewer introduces in the interview  room need not be true. As an interviewer, when you suggest a set of facts or circumstances to the subject that’s being interviewed, that is not true, that is a problem when it comes time for trial. I have tried to encourage California POST to police this stuff because it’s an unrealistic burden on a chief or on a sheriff for them to know what’s buried 30 or 40 pages into the curriculum that’s being presented to their people.

When it comes to improving their investigative interviewing practices, what are some easy, low-cost steps that police departments can put into place right away and what are some of the broader reforms that need to take place?

They should have their officers and detectives attend a science-based interviewing class. There are three-day formats, there’s a 20-hour version that’s in the CA POST ICI Core class, and then the full 40-hour class. This training is basically a framework that really the elite detectives have adopted. The training includes how to prepare to do the interview, understanding the things you should be looking for during the course of the interview, the various types of interview methodologies, including the cognitive interview, and more.  One thing I would really like to see is that the cognitive interview should become the standard for use of force investigations. It produces much more information and in no way does it become an adversarial type of interview with the officer involved.

If you had to give advice to a local police detective about to sit down for an interview with a suspect who had been arrested for a serious crime, what would your advice be to the detective on how to approach the interview?

Be genuine. Go into the interview and be genuine. There’s a retired two-star Army general named Doug Stone. When the Iraqi prison debacle took place in Abu Ghraib, he was asked to take over that prison by General Petraeus. He had no prior background in interviewing or interrogation nor prison management but now he has arguably interviewed more members of ISIS and other terrorist organizations then essentially anybody else. His method was to go into the interview and say, “My name is Doug Stone. I represent the United States government. I am a United States Marine. I am not your friend and I’m not going to do anything to change your custody status. I’m not going to get you moved. I’m not going to get you food. I can’t do any of those things, nor would I. What I am going to do is ask you if you’re willing to tell me your story. If you would tell me how it is that some kid from Paris, England or somewhere in the United States, ended up carrying an assault rifle in Syria, I would very much appreciate it. Would you tell me the story of how you got to be here?” It was short and sweet, and a very high percentage of people would tell them their whole story. We have to realize that people who commit violent crimes are statistically far more likely to tell you about it, what they have done, what the circumstances are, if you approach them in that way that establishes a human connection with them; not being nice, not being overly friendly, but a genuine human connection. This makes you appear to be very competent at your job and that is the best way to approach somebody when you need to get information from them.