Crime in San Francisco’s Urban Renewal Area
12 October 2009
We’ve been using SpatialKey to look at San Francisco data downloaded from DataSF.org. There are mountains of interesting data available for San Francisco, but the crime data from the SFPD is one of the most interesting datasets. When you load in the crime data you instantly see some powerful images, which show the intense concentration of crime in certain areas of San Francisco.
It’s amazing to see how concentrated this data is around the Tenderloin and a few other areas (along Mission St near 16th also has a high concentration). Take a moment and look at the image above (click to get a larger view). If you were to draw a line around the worst parts of San Francisco what would that shape look like? Maybe something like this?
What’s amazing is that this shape was drawn by the city when they defined an “Urban Renewal Area.” The shape is available to download from the city’s GIS catalog. That shape was defined in 2002 as part of a federal Housing and Urban Development (HUD) program. One of the key goals in targeting that areas was to reduce crime. The following paragraph defines one of the five stated goals when the area was defined:
Reducing Crime
The City of San Francisco has a crime reduction strategy that is a multi-layered approach addressing: general crime prevention education; programs targeting at-risk youth (prevention); diversion programs; programs targeting incarcerated individuals to reduce recidivism; and post-incarceration programs to reduce recidivism.
That was almost 8 years ago, but the crime data in the image above is as recent as last week. There are of course many ways to interpret this data. It could indicate that the city is not making much progress reducing drug crimes within the Urban Renewal Area. Or it could mean that the city is actively targeting the area (which will lead to higher arrests) and that the indication of higher concentrations in the Urban Development Area is a good thing.
Comparing the Urban Renewal Area to the rest of SF
To put things in perspective we can compare the crime within the Urban Renewal Area with all the crime outside of the area. The image below shows the map filtered to include only crimes within the Urban Renewal Area. The report includes the total count of crimes within that area, as well as the total count of crimes in the city as a whole (including the area).
We can see that in the entire city there were 14,653 crimes. Out of those crimes, 4,291 occurred in the Urban Renewal Area.
29% of all crime in SF occurs in the Urban Renewal Area
The above statistic is for all types of crime (of which theft is the most common in the city overall). We can see by the distribution by crime type that there’s a difference in the ranking between the city as a whole and the Urban Renewal Area. Inside the Urban Renewal Area, narcotics crimes are the number one crime type (versus theft in SF as a whole). The report is even more interesting when we filter to only look at drug crimes:
Out of 2,673 total drug crimes, 1,875 occur in the Urban Renewal Area.
70% of all narcotics crimes occur in the Urban Renewal Area
Again, please keep in mind that the data only shows where the police are arresting people (see notes section below). And this is only one slice of time, from July 25 to September 20, so we don’t have the previous historical data to see any kinds of long term historical trends.
Try it for yourself
You can open up the sample report that we created to visualize these crimes. The report loads with the crime data on the map filtered to only include drug crimes within the Urban Renewal Area. It also includes another instance of the same crime dataset loaded in (but not shown on the map). That second dataset is used to show the total count of all crimes in San Francisco as well as the distribution by type of crime for the entire dataset.
Notes on the data
The police department provides a feed of the last 90 days of crime incidents as a shapefile. The dataset used in the article was downloaded on September 21, 2009 and includes crime records from June 25, 2009 to September 20, 2009. Additionally, the city’s GIS department provides the shapefile for the Urban Renewal Area.
It is important to note that this is data of active police activity (ie arrests, citations). This means it is not a comprehensive dataset of where crime occurs. This is data about where the SFPD is arresting people. This is an important distinction to keep in mind. An increase in the number of arrests in a certain area may very well be a very good thing indicating that the police are focusing on certain problematic areas, not necessarily that actual crime in those areas is on the rise.
This is the second part of an ongoing exploration of publicly accessible San Francisco data from DataSF.org. Please see the other posts in the series.
The images and reports in this post were created with publicly accessible data. We have no association with the San Francisco police department (but we’d love to, so contact us if you’re from the SFPD and want to use SpatialKey).
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