Academics Confirm Major Predictive Policing Algorithm Is Fundamentally Flawed (vice.com)

An anonymous reader quotes a report from Motherboard: Last week, Motherboard published an investigation which revealed that law enforcement agencies around the country are using PredPol -- a predictive policing software that once cited the controversial, unproven "broken windows" policing theory as a part of its best practices. Our report showed that local police in Kansas, Washington, South Carolina, California, Georgia, Utah, and Michigan are using or have used the software. In a 2014 presentation to police departments obtained by Motherboard, the company says that the software is "based on nearly seven years of detailed academic research into the causes of crime pattern formation the mathematics looks complicated -- and it is complicated for normal mortal humans -- but the behaviors upon which the math is based are very understandable."

The company says those behaviors are "repeat victimization" of an address, "near-repeat victimization" (the proximity of other addresses to previously reported crimes), and "local search" (criminals are likely to commit crimes near their homes or near other crimes they've committed, PredPol says.) But academics Motherboard spoke to say that the mathematical theory that is used to power PredPol is flawed, and that its algorithm -- at least as pitched to police -- is far too simplistic to actually predict crime. Kristian Lum, who co-wrote a 2016 paper that tested the algorithmic mechanisms of PredPol with real crime data, told Motherboard in a phone call that although PredPol is powered by complicated-looking mathematical formulas, its actual function can be summarized as a moving average -- or an average of subsets within a data set. "The academic foundation for PredPol's software takes a statistical modeling method used to predict earthquakes and apply it to crime," reports Motherboard. "Much like how earthquakes are likely to appear in similar places, the papers argue, crimes are also likely to occur in similar places. Suresh Venkatasubramanian, a professor of computing at the University of Utah and a member of the board of directors for ACLU Utah, told Motherboard that earthquake data and crime data are, naturally, collected in different ways."

"I would say in our mind, the key difference is that in earthquake models, you have seismographs everywhere -- wherever an earthquake happens, you'll find it," Venkatasubramanian said. "The crux of the issue really is that to what extent are you able to get data about what you're observing that is not also totally on the model itself." "If you build predictive policing, you are essentially sending police to certain neighborhoods based on what what they told you -- but that also means you're not sending police to other neighborhoods because the system didn't tell you to go there," Venkatasubramanian said. "If you assume that the data collection for your system is generated by police whom you sent to certain neighborhoods, then essentially your model is controlling the next round of data you get."

Comments

Re:Police presence leads to predictable results

[Anonymous Coward]

By targeting a portion of a city or neighborhood with more LEOs, you will create more arrests there.

That only works if there's something to arrest people for.

There are undoubtedly several areas in virtually every city that are predisposed to criminal activity... areas that have a high concentration of poor people or others that are resigned to accept more overt peddling of the drug and skin trades, for instance..

So what? Abandon the people living there by letting criminals have free reign? I love that the "solution" to politically inconvenient crime all over the Western world is to simply stop policing said crime because it proves the "wrong" people right. Problem solved, once and for all! ONCE AND FOR ALL!

By all means, send more patrols to the nice, rich neighborhoods. I'm sure they'll be happy about more police presence. After all, their homes get extra protection and they can avoid the bad parts of town. Just don't blame the cops when the problem areas deteriorate even further.

Re:A city

[LostMyAccount]

I think the definitions of under/over-policing are too dependent on the number of police available.

We call an area "over policed" if it seems like there are too many police patrols based on the amount of crime, when it seems to actually be driven by a sense that there are not enough police available in higher crime areas because they are misallocated to low crime areas.

I wonder if these terms would somewhat melt away if there were just more police overall? I would argue that the use of patrol cars and radios have created a false economy that suggests we can get away with too few police because they can be "efficiently" routed to places where crime has been reported. Generally low crime areas become effectively under-policed themselves and then become more susceptible to crimes of opportunity like burglary.

This is exactly what happens in my part of the city where I live, especially once warm weather hits. The crime rate is very low generally, but there's a huge uptick in burglary during spring and summer. Police and civic officials say there's nothing that can be done, mostly due to a lack of resources. The counter-argument is that more police patrols would increase criminal risk and reduce opportunity.

If you consider a thought experiment where the amount of police cars is held very low and most patrolling would need to be done in a non-motorized fashion, you would need more overall police since you couldn't just send patrol cars in response to criminal activity and zero police presence wouldn't be an option, either. Low crime areas would wind up with less criminal opportunity due to a more regular and permanent police presence.

The other dynamic that seems to drive low policing levels in generally low crime areas is the perception that since most of the crimes that do occur are property crimes, they are a low priority because the residents are generally affluent and have insurance which more or less eliminates the "victim".

If property insurance were much more expensive, say most people had a $10,000 deductible or higher and thus were self-insured for all amounts below that, I think property crime would get more police engagement. Victims would be more or less permanently victimized by material losses, since they would be very expensive to replace.

Doesn't this just show

[rsilvergun]

that violent crime is less common then we like to think? Of course a small percentage is responsible for all violent crime. There isn't enough to go around.

Also, not sure about Sweden in the 80s but in America, even today, our prison system chews you up and spits out broken people. That's been equally well documented.

Finally pre-90s is a bad place to get crime statistics from. Lead in the air was pretty obviously creating unhinged people. Again, there's plenty of studies to back this up because it's the only thing that can explain the across the board drop in crime.

That's not solving crime

[rsilvergun]

that's corralling it. Stick with me on this, it's long.

I saw this in my old town (I live in an apartment full of Indian H1-bs now and while they do take my jerbs they're about the least criminal people on earth if you don't count them hacking my cheap router from time to time).

I used to live in a cheap, working class neighborhood. Up the street were crack houses galore. Never once did they bother me. Only trouble I ever had was from a loser friend who's girlfriend robbed me.

I used to wonder why and then I found out. "Broken Window" policing is actually "Busted Heads" policing. My bud lived in one of those crack house apartments following a bad divorce (only thing he could afford/get after getting his credit destroyed). Got robbed, they caught the guy when his apartment manager went into the apartment and recognized his stuff there. They released the guy a few days later and he was still living next door to my bud when he finally got his credit fixed and moved out.

That was OK because they'd kept the crime inside. Every now and then one of them would venture out of their little hell hole and rob a liquor store or something.

The cops would come down like a ton of bricks. Everyone got arrested. And since they all had at least some pot half were probably gonna do a year or two in the clink. Especially the Dads, who would take the rap for the pot so the mom could at least stay out of prison. And during the raid you better believe heads got busted like crazy.

This kind of shit is used to force the lower caste to stay in their lane. Keep their head down. It's the nastiest form of oppression possible. It lets you and me ignore the problem of widespread poverty because when the poor make trouble there's a cop there ready to beat them the fuck down and a private prison system happy to lock 'em up for 3-5 years.

This is also why the drug war hasn't ended. Locking up randos for minor drug crimes is how you keep those folks on edge.

Now, you might be thinking, so what? They're criminals anyway. That's all well and good, but think about it. When Capitalism goes south what's suppose to fix it? The Answer is that Mr Factory Owner won't let the country go to shit because he lives in it. But Mr Factory owner and even his middle class servants can use tricks like this to control the populace why bother? What's to stop him from letting everything go to shit except where he lives? This is where oligarchy comes from.