It's hard to construct a principled, narrow argument against profiling. If you have a single piece of exclusionary information, it's ludicrous to conduct a bunch of searches which are guaranteed to be worthless in the name of equality. (Leaving aside the accuracy of the tip for now.) And yet on a broader level, it's apparent that profiling can have all kinds of awful side effects.

An obvious example (and the metaphor carries) is secondary crimes discovered in the course of an investigation. There's another narrowly sensible rule: if a cop stops you for a broken taillight, they shouldn't have to ignore a corpse sitting in your passenger's seat. But combined with profiling, it produces a system where often-profiled people get the law enforced against them far more harshly than other groups. Add to that the cost and stigma of being investigated (a day in jail while innocent is a great way to lose a job), and you have a system where utterly sensible enforcement produces consistently biased harms.

The metaphor here carries really well. Imagine if those Kansas farmers torrented a bunch of movies, or that Seattle privacy advocate had a bit of marijuana. Well, those things are illegal, but it's still not fair that shoddy profiling amounts to selective enforcement against the profiled.

Even if you never, ever get incorrect data or wrongfully convict someone, profiling with limited data causes all kinds of secondary harms. This is a great non-racial example of why we should worry about it regardless of accuracy.

The problem is that the main true benefit of the information is to exclude people, but that isn't how people use it.

Suppose there are 2 million people in an area and you know some demographic information about the perpetrator that will allow 95% of them to be excluded. That is useful information.

But the probability that a random person in the relevant demographic is the perpetrator is now 0.001%. The demographic contains 100,000 people and one perpetrator.

The fallacy is in assuming that just because not being in the relevant demographic is enough to exclude you, that being in the relevant demographic should by itself be enough to suspect you.

[1] https://en.wikipedia.org/wiki/Base_rate_fallacy

That's still a much higher probability than 1/(2 000 000) so I am not sure what is your point there to use numbers.

"Oh, to catch the thief we are going to stop 100000 people" sounds absurd, after all.

Of course you can use the clue to exclude a bunch of people, but were you going to go around arresting random people on the street without this? Of course not, so why do it after.

There are more than enough documented cases of rape, assault and other crime in which the victim could not identify the perpetrator with any degree of certainty.

Profiling is an important tool in law enforcement but it works when it's built on proper evidence and statistical models not sketchy witness reports.

I skipped accuracy to observe that even correct profiling has problems, but it's hugely important to see that over-reliance on profiling is a threat to solving cases.

The memory and facial recognition stuff starts here http://lawcomic.net/guide/?p=3034

You hand-wave this part away too easily. It's precisely the reason that all protections in the legal system need to exist. If you hand-wave away uncertainty about facts, then there's no need to have warrants, reasonable suspicion, right to an attorney, trials, etc.

Modifications to vehicles here are mostly not permitted or have to be certified by an engineer, including engine modifications.

Now it is clear to anyone that say, a Nissan Skyline, is much more likely to be modified with non-permitted modifications than the station wagon taking the kids to school.

Yet there are many complaints from Skyline drivers that they are constantly being stopped and it's not fair treatment.

So the argument from one side is "We know these cars are often modified, so we use that information to inform who we stop for spot checks". The argument from the drivers is of course "I did nothing wrong so I shouldn't have to deal with constantly being pulled over".

The challenge for me is that both sides make sense, yet there is clearly downsides to cattering to either side too.

Without the informed stops you will get less illegal cars off the road, with the stops you incur on peoples privacy and ability to go about their day.

The unbiased solution would be to stop more cars but randomly. The Skyline drivers still get stopped just as often, but so does everyone else so they can't say it's unfair.

But that is dumb, and only really solves the problem of political correctness.

The other option is to just accept that more modified cars will get away with it for longer.

Now there are other options in this circumstance, like mandatory vehicle inspections each year for example.

But thisbone thought experiment really made me think deeply about racial profiling and how complex the issue really is, and how damaging it can be to the individuals being profiled.

To be clear, I think racial profiling is far too damaging to be a solution to anything. But I can see the logic path people take to get to it. Even if they do not make the next step to seeing the damage it causes.

>> We know these cars are often modified, (b)

Note that those are not the same: (a) means "of all cars modified, more are Nissan Skylines than station-wagons"; (b) means "of all Nissan Skylines many are modified".

Police officers will want to know whether (b) is true, so that they can decide whether stopping Nissan Skylines disproportionally often is justified.

Unfortunately, (b) really does not follow from (a). For instance, (a) is true even if there are 0 modified station-wagons and a single modified Nissan Skyline. If only a small fraction of Nissan Sklyines is modified, cops are going to have to stop many, many Skylines before they hit one of the few modified ones.

Even worse, the only way to know how many Skylines are modified is to check each and every one of them (or stop "enough" of them and extrapolate).

On the other hand, cops will want to catch any illegally modified car. So they have to wonder how many other modified cars they let slip by if they're going after Nissan Skylines more than other cars.

If the cops wanted (or were able) to do proper data-driven policing or whatsitcalled, they should make a list of all the types of car they found modified in a particular time period, count how many times each type was modified, divide by the total and go after the ones with the highest ratio, and that only if the ratio is "high enough"- which again depends on exactly how many cars were modified in that time period.

But of course, all this is hard to do and costly, so cops will go by instinct and probably apply unwarranted prejudice- and get very sub-optimal results.

I'd love to see a cultural narrative and expectational shift in the US, through which the act of simply arresting anyone at all is seen as a gross affront that only occurs on a preponderance of evidence of provable wrongdoing, else LEO is seen as having failed to do their job, serve their community, and are held accountable. A raise in the standards of policing that includes significant penalties for arrests that lead to dropped charges, no prosecutions, provable errors, etc. I also think we need to ban layering on charges like resisting arrest and other such nonsense that have become obvious tactical weapons in LEO misbehavior with citizens. We need a serious shift from automatically granting LEO the benefit of the doubt and nearly impenetrable immunity. Hell, treat it more like we treat politicians—term limits of wielding power and renewal via community review and acceptance of officers and their behavior. This would obviously be more difficult with federal LEO, but if we could change the local forces, perhaps that'd be a good enough start in people's lives.

The more recent example would be NextDoor, who learned the same lesson and experienced the same accusations:

http://www.nytimes.com/2016/05/19/us/website-nextdoor-hears-...

This is not to disagree with you per se, because I do see your edited clarification at the bottom, but one of the problems here is assuming that the eye witness is correct in labeling the individual as "an Asian male" (per your example). Perhaps this is not true. Perhaps he is a short male with black hair, but not necessarily Asian. Perhaps he has some other ethnicity and will actually be overlooked by the police because of the assumption that the witness/victim has labeled them accurately when this may not be the case at all. (I will add: People are also sometimes misgendered.)

It also helps if you've ever been stopped by a police officer for any reason, such as a traffic stop. I've been on a couple of ride-alongs so I've also witnessed it from the officer side. When you hear of someone complaining about just being searched (as opposed to being beaten/arrested/shot), it can sound like whining. Unless you've been the target yourself and you've at least experienced how damn inconvenient it is (regardless of any racial motives from the officer). You really have to be the model of patience to go through that process and think, at the time, "Nevermind me being late, he's just doing his job!"

Imagine being stopped like that as a not-uncommon part of life, just because someone of your general descriptor did some assholish thing. Besides the search/frisk/force part, I think the most annoying thing is how hard it is to argue against that logic without sounding like a politically-correct whiner.

http://europeforvisitors.com/paris/articles/paris-gold-ring-...

(note in the link above, the writer says it happened to her 3 times in an hour. I had it happen one right after another, as if the second/third person didn't see me push the first one aside. So it's not just an Asian thing, I was just saying the rate that I perceived is how I empathize with being stereotyped at a quick glance)

There has to be a site somewhere listing them all.

The big difference being the cumulative nature of peoples' experiences. If the same police are repeatedly exposed to a disproportionate amount of crimes being performed-by(or accused) by a specific group, then it would only be logical for them to naturally stop/search that specific group more often. It's a game of numbers, and I see no reason for it to be demonized as much as it has been as some "systemic oppression". As long as the police don't falsify reports that exaggerate those numbers, and behave in a civil manner towards complying citizens, then it should be "okay".

Personally, I would say that profiling by race and gender alone is way to wide of a search-criterion. For all we know, the police are actually using other side-properties of the individuals in order to profile them more specifically, yet on the surface to others it appears crass and simply based off crude properties such as race/gender. I.e. it may even be a layered approach where they "back-off" when they hit a dead-end in their search through the "good indicators for being a criminal or have just committed a crime".

E.g.: Broken tail-light -> hiding face behind hoodie -> oh, well spoken individual that just lost a family-member, must be fine.

Or: Broken tail-light -> hiding face behind hoodie -> hmm's and haw's when asked to leave vehicle for DUI test -> acting aggressive -> etc.

Your post focused on the cumulative nature of the police experience, but completely neglected the cumulative nature of the minority's experience. Therefore I downvoted you.

Edit: Grammar.

The "accused" part is the whole point. If police accuse a particular group disproportionally on the basis that they accused them disproportionally in the past, then we have a problem.

And that seems to be the case with racial profiling- that it builds upon the misconceptions of the past and therefore perpetuates them into the future.

It's really a case of GIGO, "garbage" in this case being historically prejudiced, and therefore bad, data on who should be suspected.

Of course, as others said, if you suspect and so search a particular group disproportionally often you may reasonably expect to also charge that group disproportionally often, even if that group has the same amount of perps as every othe group (which you leave well enough alone).

Another objection: there's no good reasons for police to be un-civil, even if someone is not complying. If the citizen is being a bit difficult and the police office responds in kind you can bet the situation is going to get out of hand - and who knows where it will stop? And because it's the officer that has the clear upper hand in an aggression situation (they can call backups, and their backups can call backups -with armored cars) it's the officer that has to remember to put their personal feelings aside and be professional.

Also, cops aren't the only ones who have to deal with rude and unprofessional behaviour at work. Everyone learns to deal with that sort of thing and the best way is always to set your ego aside and avoid escalation.

It takes two to tango and all that jazz.

And a last objection: that's a crap (sorry) way to profile people. A kid with a hoodie talking trash to a cop is most probably a teenager trying to grow up -and failing, currently. Give them the time to succeed and go bust someone actually doing some harm. Everyone 'll be the better off in a world with more adults than juvenile idiots.

How often do you guess real perps go looking for trouble with the police? I'd guess, not very.

That's an absurd analogy. An IP address isn't perfect, but it's far more specific than knowing the perp is an "asian male." What's the size of the universe of people who might have had the same IP address over a given period of time? A few?

Anyone can use my laptop and "have" the same IP as myself.

In truth, nobody "has" an IP address. A computer has an IP address. Who can tell who is using a particular computer at a given time just by looking at an IP address?

In that sense an IP address is a way, way more tenuous connection to a physical person than a description of (apparent) race and gender.

No, it's not - one example the article lists is a Tor exit node.

In residential settings, there's a collation that whoever owns the router is likely to own the devices on the LAN - but there are also enough cases where this isn't true. Hotels, universities, cafes. Also, Tor exit nodes or people with compromised Wifi. I'm sure it's possible to come up with more scenarios. As for a statistical probability, no idea. Is 80% or 95% acceptable? I think that's EFF's argument, that there's still enough room for error.

[0] https://news.ycombinator.com/item?id=12561381

There's only just under 4.3 Billion IPv4 addresses available. And you can write off a decent chunk of those as being not available for public use.

As of right now there are only 891 listed Tor Exit nodes.[1]

[1]https://www.dan.me.uk/tornodes

https://metrics.torproject.org/userstats-relay-country.html

http://www.foxnews.com/tech/2012/06/06/internet-grows-by-tri...

I am indeed guilty of ignoring details when indifferent.

There have been way to many discussions with one side claiming using certain kinds of evidence is unethical, and another side claiming the evidence does have some statistical power.

As far as I'm concerned most of those issues would be resolved if people actually cared to check they had a probable cause before doing anything, most objectionably evidence fails that test, and if it doesn't it shouldn't be ignored.

It's from the UK, which I know has a very different situation to the US for race relations, but after 10 years of reform of the stop and search laws (to reduce racism and needless profiling) the UK recently found 25% of all stops illegal. One of the reforms required the police to record the reason for a stop - they either hadn't recorded anything or it was inadequate for 1 in 4.

Given the hugely higher number of stops of minorities, it's easy to see that they'd be identified in more crime - stop 10x more people of a group and you'll find more weed etc.

What hasn't been shown yet is evidence it's an effective crime fighting tactic, and it's easy to see why it causes minorities to distrust the police.

Telling someone to ignore the fact that group X is Y% more likely to commit a crime is very unlikely to work (since purposely ignoring something is somewhat contradictory). You'd likely get better results by asking someone why they did something despite lacking sufficient evidence.

By definition every investigation technique is designed to be discriminatory in the proper sense of the word since you discriminate using the evidence you have so far.