Slide 1
EL CARTÓGRAFO
EN SU LABERINTO
How hack journalists managed to map out
a local crime database — and how you can too.
A remembrance by @palewire
Slide 3
I can’t speak Spanish, but I am a fan.
Slide 4
My name is Ben.
I sometimes go by @palewire.
Slide 6
Our team is called the Data Desk.
We turn databases into news.
Slide 7
That means we write code.
Slide 8
But we still remember English.
Slide 9
We make things like...
Slide 26
YOU GET THE POINT
(Now back to the lecture at hand.)
Slide 28
CHECK IT OUT
http://maps.latimes.com/crime
Slide 37
Hey. You.
Build us a
crime site.
Meredith Artley
latimes.com boss, circa 2008
Slide 38
WHAT WE WANTED
● Consolidate across departments
○ 15 PDs cover 88 cities in LA County
● Be more than a zillion points on a map
○ By spotting short term trends
○ Giving long-term context
○ And grouping crimes into geographic areas
people can relate with. (Neighborhoods!)
Slide 39
WHAT WE WANTED
● Consolidate across departments
○ 15 PDs cover 88 cities in L.A. County
● Be more than a zillion points on a map
○ By spotting short term trends
○ Giving long-term context
○ And grouping crimes into geographic areas
people can relate with. (Neighborhoods!)
Slide 40
WHAT WE WANTED
● Consolidate across departments
○ 15 PDs cover 88 cities in L.A. County
● Be more than a zillion points on a map
○ By spotting short term trends
○ Giving long-term context
○ And grouping crimes into geographic areas
people can relate with. (Neighborhoods!)
Slide 41
WHAT WE WANTED
● Consolidate across departments
○ 15 PDs cover 88 cities in L.A. County
● Be more than a zillion points on a map
○ By spotting short term trends
○ Giving long-term context
○ And grouping crimes into geographic areas
people can relate with. (Neighborhoods!)
Slide 42
WHAT WE WANTED
● Consolidate across departments
○ 15 PDs cover 88 cities in L.A. County
● Be more than a zillion points on a map
○ By spotting short term trends
○ Giving long-term context
○ And grouping crimes into geographic areas
people can relate with. (Neighborhoods!)
Slide 43
WHAT WE WANTED
● Consolidate across departments
○ 15 PDs cover 88 cities in L.A. County
● Be more than a zillion points on a map
○ By spotting short term trends
○ Giving long-term context
○ And grouping crimes into geographic areas
people can relate with. (Neighborhoods!)
Slide 44
You have a right to the
data.
THE LAW
Slide 45
You have a right to the
data.
But the police don’t
have to automate a
feed for you.
THE LAW
Slide 46
That put us here.
Slide 47
These two departments
Cover 69% of population and
89% of territory
Slide 48
We’ll give a secured FTP
file to you, and only you,
becase you’re the
newspaper, you asked
nicely and you won’t go
away.
Los Angeles (city)
Police Department
Slide 49
We’ll post a file on the
WWW, for anybody, because
then we can point anybody
who asks for this data at it.
Los Angeles County
Sheriff’s Department
Slide 53
Back here again.
Slide 54
Set up server to do the math.
Slide 55
Per capita for broad context
● All violent crimes
● In each neighborhood
● Over the past 6 months
● Divided into neighborhood population
● Results in crime rate per 10,000 people
● Repeat with property crimes
Slide 56
Per capita for broad context
● All violent crimes
● In each neighborhood
● Over the past 6 months
● Divided into neighborhood population
● Results in crime rate per 10,000 people
● Repeat with property crimes
Slide 57
Per capita for broad context
● All violent crimes
● In each neighborhood
● Over the past 6 months
● Divided into neighborhood population
● Results in crime rate per 10,000 people
● Repeat with property crimes
Slide 58
Per capita for broad context
● All violent crimes
● In each neighborhood
● Over the past 6 months
● Divided into neighborhood population
● Results in crime rate per 10,000 people
● Repeat with property crimes
Slide 59
Per capita for broad context
● All violent crimes
● In each neighborhood
● Over the past 6 months
● Divided into neighborhood population
● Results in crime rate per 10,000 people
● Repeat with property crimes
Slide 60
Per capita for broad context
● All violent crimes
● In each neighborhood
● Over the past 6 months
● Divided into neighborhood population
● Results in crime rate per 10,000 people
● Repeat with property crimes
Slide 63
Spikes for narrow context
● All violent crimes
Slide 64
Spikes for narrow context
● All violent crimes
● In each neighborhood
Slide 65
Spikes for narrow context
● All violent crimes
● In each neighborhood
● Over the past 7 days
Slide 66
Spikes for narrow context
● All violent crimes
● In each neighborhood
● Over the past 7 days
● Calculate deviation from that neighborhood’s
weekly average over last 3 months
Slide 67
Spikes for narrow context
● All violent crimes
● In each neighborhood
● Over the past 7 days
● Calculate deviation from that neighborhood’s
weekly average over last 3 months
● Measure against our editorial standard for alert
Slide 68
Spikes for narrow context
● All violent crimes
● In each neighborhood
● Over the past 7 days
● Calculate deviation from that neighborhood’s
weekly average over last 3 months
● Measure against our editorial standard for alert
● Repeat with property crimes
Slide 72
Wired it up to the web.
Slide 73
The app stack, roughly
Slide 79
THAT’S NICE,
AMERICANO.
But we can’t get data.
Slide 80
We turn databases into news.
(You remember this bit.)
Slide 81
We turn news into databases.
(Try reversing it.)
Slide 83
CHECK IT OUT
http://projects.latimes.com/homicide
Slide 93
Follow us.
datadesk.latimes.com
@LATdatadesk
github.com/datadesk