A major place that data science brings value is in being able to deploy resources most effectively. Police work is no exception and predictive policing has become a very popular term with resource-strapped police departments trying to deploy their forces in the most effective manner possible. Now the term predictive policing may suggest that the police are able to predict precisely where and when and by whom a crime will be committed. The kind that one might expect from say a pre-crime unit in the movie Minority Report as we see in this clip. >> Imagine a world without murder [MUSIC] >> I lost my best friend! >> I lost my aunt! >> I lost my dad! >> I lost my father! >> I lost my wife. >> Just 6 years ago the homicide rate in this country had reached epidemic proportions. It seems that only a miracle could stop the blood shed, but instead of one miracle we were given three, the precognitives. Within just one month our pre-crime program, the murder rate in District of Columbia was reduced 90%. >> They were going to be waiting for me in a car. >> He was going to rape me. >> I was going to be stabbed. >> Right here. >> Within a year pre-crime effectively stopped murder in our nation's capital. >> In the six years we've been conducting our little experiment there hasn't been a single murder >> And now pre-crime can work for you. We want to make absolutely certain that every American can bank on the utter infallibility of this system and ensure that what keeps us safe will also keep us free. [MUSIC] >> Precrime, it works. >> It works. >> It works. >> It works. >> It works. >> It works. >> It works. >> Precrime, it works. >> On Tuesday, April 22nd, vote yes on the National Pre-crime Initiative. >> In practice, predictive policing doesn't mean that you're going to have an accurate and precise prediction of the type that we just saw. Such predictions take away free will and surely we all are, even the criminals amongst us, thinking beings. With choices that we make in life, rather what predictive policing can do for us is predict probabilistically, where and by whom and when, certain crimes are more likely to happen than normal. [MUSIC] [SOUND] >> Okay Jed, what's coming? >> Double homicide, one male, one female. Killer is male, white forties. Agatha nailed the time frame at 8:04 AM. The twins are a little fuzzy on that so we'll need confirmation. Location still uncertain. Remote witnesses are plugged in. This will be case number 1-1-0-8. [MUSIC] Morning, detectives. [MUSIC] Case number 1-1-0-8. Pre-visualized by the precogs, recorded on HoloSphere by Pre-Crimes [INAUDIBLE]. My fellow witnesses for case number 1-1-0-8 are Dr. Kathryn James and Chief Justice Ryan Pollard. Good morning. >> Good morning. >> Will the witness preview and validate number 1-1-0-8 at this time? >> The private and I will validate. >> Go get him. >> Stand by. >> Time of murder 8:04 AM. >> Just working with the probabilities is enough to be able to deploy resources more effectively. In terms of having police presence in areas where their presence is most likely to be the most valuable is probably a good thing all the way around. However, one can go further. And there are cases where predictive policing have tried to identify Individuals and suggest to them not to commit crimes when the algorithm has suggested that certain individuals might potentially be so inclined. >> When the precogs declare a victim and a killer their name is embedded in the grain of wood. Since each piece is unique the shape and grain is unique. The shape and grain is impossible to forge. >> I'm sure you all understand the legalistic drawback to pre-crime methodology? >> Here we go again. >> Look, I'm not with the ACLU on this, Jeff. But let's not kid ourselves. We're arresting individuals who've broken no law. >> But they will. The commissioner of the crime itself has absolute metaphysics. The precogs can see the future and they're never wrong. >> But it's not the future if you stop it. Isn't that a fundamental paradox? >> Yes it is. You're talking about predetermination which happens all the time. [NOISE] [SOUND] >> Why'd you catch that? >> Because it was going to fall. >> You're certain? >> Yeah. >> But it didn't fall, you caught it. The fact that you prevented it from happening doesn't change the fact that it was going to happen. >> You ever get any false positives? Someone intends to kill his boss or his wife but they never go through with it. How do the precogs tell the difference? >> Precogs don't see what you intend to do, only what you will do. >> Then why can't they see rapes or assaults or suicides? >> Because of the nature of murder. There is nothing more destructive to the metaphysical fabric that binds us than the untimely murder of one human being by another. >> Somehow I don't think that was Walt Wittman. >> It was Zara Cinnamon. She designed precogs, designed the system and pioneered the interface. Speaking of interfacing, I'd love to say hello. >> To Hineman? >> To them. >> The question is not that somebody is being put into prison or being punished before they commit the crime. We all do things that sometimes break some minor rule or the other. Most of us get past these minor infractions with no consequences, and this is just the way society functions. The thing with probabilities is that they're probabilities and just to get a sense of how this might make sense and where this might cause a problem let's just make up some numbers. So let's say that the population as a whole, that one in a million people will commit a murder. Let's say that some person because of friend circle and life situation, that algorithm has determined they are a thousand times more likely than the average person to commit a murder. A thousand times is a large factor and certainly it makes sense for a police department to pay more attention to this person than to the average citizen. Recall that we said it was a one in a million chance for the average person. And this person for whom the chances are a thousand times average, it's still 1 in 1,000. So here you have somebody who is far more likely to commit a murder than the average citizen but this person still has only 1 in 1,000 chance of committing a murder. At this point, treating this person as if they were a murderer or that they were likely to commit a murder tomorrow. Just isn't appropriate because the overwhelming odds are that this person, even though far more likely than the average person to commit a murder Is still extremely unlikely to commit a murder. Probabilistic predictions can help and they can help particularly in the aggregate in terms of deploying resources, including police resources. When one is trying to exploit the value that one gets from such predictions, one should though remember what's probabilistic, and that probabilistic is very different from definite. And keep that in mind in terms of determining what the consequences to individuals are.