Flawed Map Says L.A.'s Crime Highest Next to Police HQ

CNET briefly describes how a poorly chosen default behavior has led to an online crime map of Los Angeles (on a site designed at a cost of $362,000) that shows that "a location just a block from the department's new headquarters is the most crime-ridden place in the city." I wonder how often this sort of error would completely skew things like real-estate maps that attempt to show whether houses in a certain neighborhood are worth more than those in the one next door.

Comments

Perhaps criminals are getting more brazen

[superyanthrax]

More seriously, they should probably have had the program throw an error in case they could not find a certain location rather than putting the crime report at an arbitrary location. That would have caused the problem to be discovered earlier.

Re:Perhaps criminals are getting more brazen

[Trepidity]

There's ways to balance that, depending on what your needs and visualization methods are. For example, if you know that a significant proportion of your crime reporting gives only district-level precision, not pinpointing to specific addresses, then it'd be more honest data presentation to just produce a colored-in map on a district-by-district level, and not attempt to give more detailed maps. If you do still want to give the more detailed maps, then at least average the un-localized things across the district instead of putting them all in one place.

To use an actual (fairly simple) example that came up in my work recently: say you have some date figures, most of them with years but some only with decades. The wrong thing to do is to put the "1960s" datapoint at 1965, because then you get spurious spikes in the middle of every decade. Several more correct options are: just produce decade-by-decade visualizations, or else produce year-by-year visualizations, but assign a "1960s" datapoint as a 1/10-weight datapoint in each of 1960 through 1969.

Criminal activity detection...

[RyanFenton]

It's not a legally recorded crime unless someone is caught and convicted. It's not surprising that these crime maps would show this result - the places that police officers are most likely to be, are the places where the most crime is "found".

This is akin to saying that the places where the most vehicular crime occurs are where speed traps and automated traffic cameras are located.

If you had a world with absolute and omnipresent law enforcement, and that society could somehow actually function, my guess is that the map would match a map of the average human traffic in a given location.

Ryan Fenton

Seem like a no brainer...

[__aaclcg7560]

Would you build a new police station in a crime-infested neighborhood or in a rich neighborhood that would complain about the criminals that police bring in?

Er...

[mutube]

Isn't it a good thing that the police station is close to an area of high crime? Would we rather they were really far away?

$362,000

[ortholattice]

Is this a reasonable price for what seems to be an interface between google maps and the dept's crime database? Somehow it seems to me that a motivated person could do the basic design and coding in a few days. Then add in user feedback, layout redesigns ,etc., but still, should it really take even a couple of months for one person? As a crude guestimate, I would probably feel a little greedy or overly conservative bidding 6 months, of course I don't know the spec or what's really involved. What am I missing that seems to imply two person-years or more of work?

Re:What's the problem?

[russotto]

It's hard to imagine a software glitch causing this exact behavior.

Ever enter an address into an on-line mapping program that it didn't recognize? They'll often show a map at a default location at the center of the zip code you entered. Same idea here.

Traffic accidents...

[skathe]

Aren't the vast majority of traffic accidents that people get into very near their home?

Basically, police are around the police station more than they're far away from it. They start their shift there and end their shift there. It's the hub of activity for police. So of course the high crime areas are going to appear as if they're near the police station. "Low hanging fruit" is the term for this I think. Why drive miles away from "home base" to make arrests when there's stuff going on right in your front/back yard?

One of my very good friend's dad is a police officer. Now chief of police of a small town, but when he was younger he worked in Chicago. There was a public housing project there called Cabrini Green. It was so violent, crime-riddled, and gang-controlled that very few, if any, police officers dared enter. Obviously, on a crime tracking system like this, it would appear as if this was one of the most crime-free places in the city, because so few arrests were made there, when in actuality the crimes there were at a higher frequency and more brutal.