What to do about serial offenders

Serial offenders create unique challenges. They thrive on the investigator’s inability to focus on a single crime. Besides the normal best-practice approach of rapport-based, nonjudgemental interviewing, there are two other techniques that I’d recommend using. Focus on one crime or victim at a time; start with your strongest case, and then proceed to your weaker cases. Elicit statements from them that show them to be the type of person that would do the crime.

The serial suspect will thrive on your inability to focus.

You need to be laser focused on one crime at a time. This is hard to do because it creates such a daunting task. If one crime might require a 4 hour interview, what could it mean for a series of three or more crimes? This seemingly impossible task causes the interviewer to rush and take shortcuts that they shouldn’t. Remember how you eat an elephant? One bit at a time. Choose your best case and get started.

The first time I realized that I needed to focus on one victim at a time was on a man that had sexually abused his cousins. There was a female victim and a male victim. The female was about 12 years old when he abused her, and the male was about 14 when he was abused. During the interview, the suspect made multiple comments that suggested he had (or wanted to portray) a negative view on gay men. When I got to the end of the interview, I formed the conclusion that the suspect’s guilt was reasonably certain, and I decided to interrogate him.

I intuitively knew that it would be messy to talk about both victims at once. I decided to interrogate the suspect about one victim and then the next, but which victim should I start with? His crimes against the female constituted the more serious offense due to her being under 14 so it would seem reasonable to start with the male and then proceed to the female. However, I recalled that the suspect seemed to want to portray a bias against gay men. I decided to interrogate about the female victim first even though it was the more serious charge because it didn’t require him to express a sexual interest in males.

The strategy was successful. He first confessed to his crimes against the female, and then, when he was entirely done with that, I shifted the topic to the male. He confessed to his crimes against the male too. It took patience to go all the way through with the process for one and then do the same thing for the other. At the conclusion, though, I had solid confessions about both.

The next time I thought about the process of focusing on one victim at a time was when I helped another unit interview a serial masturbator. I felt a lot of pressure to get this interview right. There had been a community uproar about this man. He had escalated from masturbating and leaving the scene to masturbating and chasing the victims. I sorted through the cases, and I saw that there were three in particular with good evidence and a fourth that was a maybe.

In the best evidenced case, the victim took a picture of him with his penis in his hand. You couldn’t quite see the penis, but it was clear from his hand, body position, and general expression what was happening. The victim got a description of his car as well. This was for sure the one to start with. The next best case had a suspect and vehicle description. This was a scary one because he chased the woman, and she fell and hurt herself badly. I forget how now, but there was another significant link to this case. Contact DNA swabs maybe? The third case had a suspect description and a license plate. The fourth was an out of county case with a not-very-good photo that generally matched his build and hair color.

Once again, I went one at a time, in depth. Something like, “There was an incident where a woman took a picture of you. Can you tell me all about that from beginning to end?” Then we go over the story. He admits to being there and having his penis in his hand, but he claims to have been peeing. I go through the story, testing it asking tough questions like, “Have you ever masturbated in public?” After a full interview (alibi, means, opportunity, motive etc), I move to the next best case, and I do another full interview. Then on to the next one.

Ultimately, the man confessed to having masturbated something like 9 times in public. He said that he got a thrill out of the possibility that he might be seen, but he claimed that he did not want to actually be seen. I think that this case would have been quickly derailed if I asked one or two questions about each case before moving onto the next one. It’s tempting to see a case like this as having such overwhelming evidence that an extended, non-accusatory interview seems pointless. This interview took me over 4 hours, but I got the truth one case at a time.

The next tactic I’d recommend for dealing with serial offenders is to elicit statements from them that show they are the type of person that would commit the crime. This, in my opinion, would be particularly good when you have a series of crimes without any one crime having really good evidence pointing directly at the suspect (video, DNA, reliable eyewitnesses). Without great evidence, it is difficult to make a strong assertion of confidence in their guilt. This is common in child abuse cases where physical evidence on delayed outcries is scarce.

For example, a coworker of mine had a case with a school teacher that had students over the years indicating he had had sexual contact with them. For a variety of reasons, the statements from these children had problems. They didn’t know exactly when it happened. They had outcried then recanted. The school seemed to have meddled over the years. Essentially, there was a lot of smoke but not a lot of fire. What to do?

Without focusing on one specific crime, you can search for means, motive, and opportunity. Means is the physical ability to perform the act, so this is not particularly difficult. Motive is richer ground to develop. Search for both his motives and the motives of the accusers. Does he have a sexual interest in children? Has he been questioned by police or his employers about sexual contact with children? What is it about him that would lead children to lie about him? These are all general questions without being specific to one case, but they can point you to people or situations you need to know more about.

Without great evidence, it is hard to say for sure what happened, but there are responses that suspects will give you that will increase your confidence that you have the right guy. For example, here is an exchange I had in a recent interview with a father accused of sexual contact with his daughter:

Me: “Has your penis ever had contact with her face?”

Him: (confused look on his face) “Not that I know of?”

You won’t be shocked to hear that this response gave me great confidence that I had the right guy. In the more general cases you might ask, “Have you ever been alone with a naked child that wasn’t your own?” “Have you ever thought about robbing somebody?” “Is there any reason why your name would have come up in a burglary investigation before?” I can’t speak for how scientific it is, but, on a gut level, if a man responds to that question with, “Not that I know of?” You’re probably onto something.

Then you explore opportunity. Continuing with the example of the accused teacher, you might ask, “Were kids ever over at your house?” “Did you have private meetings with the children?” With issues like this you are listening for their responses and looking at what they do when they respond. Many times it will be apparent which questions the suspect has problems with.

I am NOT saying that we should hope to charge people on mere suspicion. You still need good evidence. You should always be testing your theories with counterarguments like, "What if they are innocent?” “Is there another explanation for this fact pattern?” I AM saying that this suspect came on your radar somehow. You owe it to the victim to seek information as diligently and skillfully as you can. In my experience, guilty offenders that are questioned in this way end up making graduated (ever expanding) admissions (before I told you that he never saw my penis but come to think of it…) or telling stories that are so ridiculous they are suspicious (I’ve lived with my stepdaughter for 12 years, but I never hugged her).

If you decided to move into an accusatory interrogation¹, you might consider starting nonspecific and then gradually becoming more specific. “There’s no doubt that you’ve had sexual contact with children” instead of “There’s no doubt you [specific actions with specific child].” In a robbery series, you'd want to start with something like, "You've definitely been involved in taking people's things" instead of "You definitely robbed the woman at 7th and Cedar last night." Then, once they have admitted to general acts, you can become more and more specific.

In summary: for serial offenders, focus on one crime at a time when you have well-evidenced cases. Otherwise, explore the general motive and opportunity issues while looking for issues to narrow in on.

1. Remember: if you aren’t reasonably certain that your suspect did it at the end of your interview, don’t interrogate.