Here’s a personal fact about me: I’m a true crime buff. I often listen to true crime podcasts and audio essays while unwinding at the end of the day, or during my time at the gym. (My wife finds the idea of listening to podcasts that talk about gruesome crimes to be an incomprehensible way to unwind, and she doesn’t understand how I can even enjoy horror movies.) One thing I’ve noticed is that in many of the cases I have heard of the criminal drastically overestimating his chances of getting away with the crime.
One of my favorite shows in the genre is called The accidental criminal. In this show, the host, Simon Whistler, is given a script by one of his writers that he has never seen or read before recording. He then reads it for the first time on the show, frequently breaking the script to add some of his own side commentary. Very often this takes the form of him absolutely roasting the criminal from the episode for their ineptitude, both in committing their crime and their attempts to cover up what they’ve done, such as this case involving a young man. This is a more famous (or infamous) case Leopold and Leotwo young men who were convinced they were capable of masterminding the perfect crime, but whose actual achievements weren’t exactly on the level of Professor Moriarty.
In a recent post I touched on Gary Becker’s model of criminal behavior again. To summarize briefly, Becker modeled choices about committing crimes as a form of rational behavior. Criminals take into account the expected proceeds of their crime and compare it to the expected costs of committing the crime. The expected costs depend on the likelihood and severity of the punishment. A severe punishment may provide little deterrence if the chance of being punished is minuscule. And an almost certain punishment may provide little deterrence even if the punishment itself is trivial. To give more specific figures, a 0.1% chance of a €1,000 fine provides as much deterrence as a guaranteed €1 fine – not much. In the case of Leopold and Leob, even though their crime carried the possibility of a death penalty or life imprisonment, their (false) certainty that they could avoid detection negated any deterrent.
This emphasizes an important point. When we talk about criminals behaving rationally and taking into account the probability of punishment, what is relevant is that of the criminal himself subjective estimate of the chance of being caught and punished. When economists talk about people making “rational” decisions, that doesn’t mean their decisions can’t be wrong or ill-informed. If a criminal drastically underestimates the chance of being caught, his estimate of the expected costs of the crime will be lower than the actual costs. As a result, they might end up committing a crime that, in their own eyes, is “not worth doing.”
This does not show that the criminal behaved ‘irrationally’, as economists use the term. But if criminals systematically underestimate the likelihood of being caught and punished for a crime, it would lead to criminals overproducing their crimes; criminal acts that might have been deterred had they better understood the likely outcome will fail to be deterred. This provides one argument in favor of harsh punishment for crimes. If criminals underestimate the expected costs of their behavior because they systematically underestimate the likelihood of punishment, the only way to increase the expected costs is to increase the severity of the punishment.
But sometimes criminals can estimate their chances of getting caught more accurately. Take the case of Joseph DeAngeloknown by many names, best known as the Golden State Killer. His criminal activities continued from 1974 to 1986. He was finally arrested in 2018, 40 years after his spree ended. It turned out that DeAngelo was a police officer. As a result, he knew far better than most how to avoid detection and how investigation would be conducted. For example, he was very careful never to leave fingerprints behind. But there’s something particularly unusual about DeAngelo: the forty-year period between when his crime spree ended and his arrest. He has not struck again in those forty years. This is remarkable: serial killers almost never stop. A serial killer who stops killing is so unusual that it is usually taken as a sign that the killer himself has died or may have been arrested for another crime.
So why did DeAngelo quit? Well, shortly after his final appearance as the Golden State Killer, something happened that caused quite a stir in the law enforcement world. The first trial in which DNA evidence was used to secure a murder conviction took place. This put DNA evidence on the radar for law enforcement officials everywhere – including DeAngelo. And he realized what this meant. Although he had taken great care to avoid leaving behind any evidence that could link police investigators to him, he also knew that his DNA would be present at previous crime scenes and very likely also at new. Suddenly the ‘probability of punishment’ variable for him shot up dramatically, and combined with the fairly high punishment he faced for his actions, committing further crimes suddenly became ‘not worth it’ anymore.
And so, a very brutal and pathological serial killer whose criminal acts had been intensifying and escalating for over a decade came to a sudden end. This makes perfect sense in the context of Becker’s theory of crime. And while rational choice theory is not a perfect model to describe all human behavior under all circumstances, I think this shows that it explains a much larger scope than most give it credit for.