Crime

Posts about policing and criminal justice.

Recent posts

Sketching D.C. Crime Data With R

A car burglar last week nabbed a radio from our car, prompting me to think (once again) about crime in Washington, D.C., where I live.

I wanted to know if certain crimes were more common in particular neighborhoods, so I downloaded a list of every serious crime in 2012 from the city’s data portal. The data contained about 35,000 reported incidents of homicides, thefts, assaults, etc., with fields listing the date, time and neighborhood associated with each case.

I used the statistical programming language R, which is great for quickly creating small multiples to examine data, to make some rough visual sketches.

First, since we’re talking about cars, the first grid shows thefts from vehicles, by hour and “advisory neighborhood commission“. These commissions are the small groups of officials who represent their respective D.C. neighborhoods on issues like real estate development and alcohol sales, among other things. (I live in Brookland, which is governed by ANC 5B). You can find your ANC here.

It’s clear that thefts from vehicles are most common in ANC 1B, a diverse, densely populated and rapidly changing section of the city. For those familiar with D.C., this is Shaw, U Street and parts of Columbia Heights. The x-axis shows the hour of the crime, and the y-axis shows the total number of crimes. My neighborhood is relatively safe, actually:

theftfromcar2012

Next we look at robberies, which appear common in ANC1A, which also contains Columbia Heights and Park View. Notice the spikes in the early-morning hours in the ANCs 1A and 1B, compared to the late-night spikes in ANCs 8B and 8C, both of which are in the far southeast neighborhoods like Anacostia and Buena Vista. These are among the poorest areas in the city. I’m not sure what that means, but it’s interesting:

robbery2012

Burglaries…

burglary2012

Car thefts…

cartheft2012

Assaults with dangerous weapons…

assault2012

Here are the homicides — all of which get coded as occurring at midnight, so we don’t get to distribution by hour. Still, the result is a simple bar chart that shows the variance by region  (7D and 8E had more homicides last year than other locations).

homicide2012

Here’s the grid with all these crimes above (also including a small number of arson cases):

allcrimes

And here’s a grid with histograms for each offense type. Simple thefts (there were more than 12,000 last year) appear to be most commonly reported in the afternoon, while thefts from vehicles are most often reported first thing in the morning — probably because victims notice the crime when they wake up.

Screen Shot 2013-07-08 at 12.32.53 PM

Again, these are just quick sketches, but they show you the power of R in exploring your data before investing time in a more complicated visualization. A look at the basic code also shows how quickly these types of sketches can happen.

Previously:

Charting Views On Gun Control

The latest New York Times/CBS News poll shows support among Americans for stricter gun control laws:

The massacre of children at an elementary school in Newtown, Conn., appears to be profoundly swaying Americans’ views on guns, galvanizing the broadest support for stricter gun laws in about a decade, according to a New York Times/CBS News poll.

This chart shows the trend:

Screen Shot 2013-01-18 at 7.52.30 AM

See the full graphic to see the interesting regional differences in Americans’ attitudes toward gun control.

Mapping Crime Data With CartoDB

Today I started playing with CartoDB, an online data mapping service that reminds me in some ways of both Google Fusion Tables and TileMill.

To start, I grabbed a simple test data set — five months of geocoded major crimes in D.C. from January to May this year — to check out some features. One I like is allowing users to query their data in the browser-based interface and filter for specific types of records.

Here, for example, I narrowed the map to show just thefts:

Assaults with deadly weapons:

Vehicle thefts:

Thefts from vehicles:

Robberies:

Homicides:

I made these maps in less than five minutes, so I’m sure there are much more useful stories to tell with the tool. There are also many, many features I didn’t explore, like the ability to style the map using Carto, the CSS-like language, rather than the UI.

Anyway, give it a shot, and let me know what you build.

Inside U.S. Prisons — From Above

A few years ago, the great Niran Babalola and I dreamed up a news app that included all inmates and prison units in Texas. We built it because the state’s database was perpetually down, and we thought the public — victims, prosecutors and inmate families, especially — should have a reliable view inside their state’s prison system. One of my favorite features was a Google satellite image of each prison unit.

Here’s what Texas’ Death Row looks like from the sky, for example:

Today I discovered a nifty new (to me) site that has similar views of most United States prisons:

The United States is the prison capital of the world. This is not news to most people. When discussing the idea of mass incarceration, we often trot out numbers and dates and charts to explain the growth of imprisonment as both a historical phenomenon and a present-day reality.

But what does the geography of incarceration in the US actually look like? Prison Map is my attempt to answer that question.

Check it out:

(via Alan Palazzolo @zzolo)

Charting Car Burglaries in DC

Last week someone burglarized our car. Fortunately the burglar didn’t get much, if anything, and a window wasn’t smashed. (Someone left the door unlocked, apparently). But it was a reminder that, even though our Brookland neighborhood is quiet and safe, we’re still vulnerable to property crimes. Then this morning I noticed that a neighbor’s driver-side window had been smashed in a burglary.

Looking at the data, it doesn’t appear that car burglaries are on the rise in our larger neighborhood, Ward 5. Residents here reported 109 car burglaries in January, for example, but only 59 in April. There also doesn’t appear to be a week-to-week uptick in April. I wondered whether the time of year makes car burglaries more likely, so I downloaded six years of major crime data (170,000 incidents of murder, robbery, theft, car theft, arson, sexual abuse, and vehicle burglary) to find out.

This chart shows the six-year trend, by month, in the city for car burglaries. There has been an uptick in recent history during May, it seems. Incidents of the offense have then leveled off before spiking again in the fall:

Our ward has shown a somewhat similar trend:

Data source: data.dc.gov

How Many Cops Does Your Local Government Have Per Resident?

Does Washington, D.C., have more cops than other cities? That’s the question I asked myself the other day after watching a patrol car drive down our quiet, residential street. I see patrol cars everywhere — much more often than I did previous cities like Houston and Austin.

There’s a reason: Among the top 50 most-populous local governments, D.C. simply has more police officers per resident, according to the U.S. Department of Justice, which surveyed large police forces a few years ago. The city has about 670 cops per 100,000 residents, well ahead of Chicago, which was second with about 472 per 100,000. Houston had about 220, and Dallas had about 260.

Of course, D.C. is the capitol and diplomatic center of the country, and it’s densely populated with pockets of high crime and poverty. So a large officer to resident rate is understandable. But it’s a bit surprising how much D.C.’s ratio eclipses that of other major cities.

This chart shows the cities among the top 50 that have the highest per-resident officer ratio:

Here are the data for all 50 cities plotted on a map made with TileMill. Larger symbols represent higher numbers of officers per 100,000 residents:

See larger, interactive version

Data source: U.S. Bureau of Justice Statistics

Mapping LA Fires

The Los Angeles Times has released a nifty interactive map and table of the recent arson fires in the City of Angels: 

Since the morn­ing of Dec. 30, a wave of in­ten­tion­al blazes has dam­aged prop­erty and left res­id­ents on edge. The fires range from the West­side to Hol­ly­wood and from the San Fernando Val­ley south to Len­nox. Nine more fires were re­por­ted Monday morn­ing. Of­fi­cials have not con­firmed wheth­er some re­por­ted fires are re­lated to the ar­son spree. The Times will up­date this map as more de­tails be­come avail­able.

I like how the fires are categorized by type — and that the Times’ data desk added a handy timeline to help readers visualize when the fires were set: