About Houston Crime Maps
Background
In the summer of 2005 I moved to Houston from San Antonio. Before my move, I wanted to see which areas of town had the most amounts of crime -- but was discouraged at the the lack of services available for determining this information. While the City of Houston generously supplied its crime statistics in a multitude of formats, they were hard to use to determine the volumes and types of crime that were occurring in the many Houston neighborhoods.
Previously, in the spring of 2005, Adrian Holovaty launched ChicagoCrime.org. I was impressed by this project, and figured that if the third largest city in the U.S. could have such a neat service, then why not the fourth largest city: Houston. Determined to complete such an endeavour, I registered this domain in July, 2005.
While I completed some of the initial back-end work that summer, school work prevented me from progressing further. In the summer and fall of 2006, I finally managed to get some motivation and published what you see today.
Disclaimer
If you haven't seen the disclaimer yet at the bottom of the page (and every page), look at it -- this website is not affiliated in any way with the City of Houston or the Houston Police Department.
It should be noted up front that the Houston City crime statistics disclaimer states:
"HPD does not provide this data as a method of determining if one police beat or area of the city is safer or more dangerous than any other beat or area. Police beats and districts vary in size, population, and density, making such comparisons difficult ... Since crime is a sociological phenomenon influenced by a variety of factors, HPD discourages data users from performing comparative analysis betweens beats, districts, or any other division of the city based solely on the information provided here."
I agree that crime is a multivariate occurrence with no single factor being determinative (i.e. location). I also believe that greater access to information enhances decision-making among both citizens and consumers. Since the data may be utilized for "a variety of research and planning purposes," by "criminologists, sociologists, legislators, city planners, and other students of criminal justice" (see disclaimer), it is difficult to believe that it is insufficient for any type location comparisons. In addition, patterns may be recognized by many laymen that might not be apparent to a single expert.
This site is an evolving project and there may be problems or "bugs" that have the potential to give inaccurate results. As such, I encourage users to be on the lookout for any problems -- help me fix them if you see something that "doesn't look right." Send bug & problem reports to hcm AT houstoncrimemaps.com
Methodology
All crime data is retrieved from the City of Houston Police Department's crime statistics page. I use the HTML formatted files, as I have no use for Microsoft's proprietary formats.
Addresses are geocoded (a process turning an address into latitude/longitude coordinates) using the U.S. Census Bureau's TIGER/Line data (2006 Second Edition). Any addresses that fail to geocode are submitted to Google for a second try. It should be noted that due to errors in geocoding or address reporting (police sometimes make mistakes), approximately 4% of crimes are not listed. These crimes are still in the database, and will become available as improvements are made.
Zip Code, Police Beat, Police District, Neighborhood, and Houston City Council boundaries are provided by the City of Houston Public Works & Engineering GIS website. Texas State House & Senate districts come from the Texas Legislature RedViewer site.
Once geocoding is complete, all data for an individual crime is given an entry into a database. This website's underlying software queries the database to get the associated information for crimes and uses the Google Maps API to generate the interactive maps.
Similar Sites
This site is not alone. Since I registered this domain summer 2005, similar sites have sprung up offering comparable services:
Crime Houston: This commercial service, launched in spring of 2006, charges up to $20/day to view a subset of the data listed here without limitations and enhanced density visualizations.
Houston Crime Maps and Statistics: Authored by Eric Carlson, he provides primitive Google Maps of Houston Crime only browsable by police beat along with some aggregate statistics.
Houston Crime Stats: This site, also powered by open source software, launched in the spring of 2006. The author, Kristopher E.J. beat me by providing the first (usable) Google Maps powered interface for browsing Houston Crime.
I encourage you to "shop around," as I am confident that you'll find that this site provides more crimes, more statistics, and superior usability than all the others.
Software Props
First of all, I wish to thank Adrian Holovaty, Jacob Kaplan Moss, Simon Willison, and Wilson Miner for devoloping the excellent Python Web Framework Django. I independently came to the conclusion to use this framework before realizing that it powered the Chicago Crime website (really! -- I didn't read the bottom of the page until a year later). The usability of that site motivated me to provide such a service for Houston, but other factors (Python, templates, tight database integration) drove me to select it separately.
Also, thanks to Schuyler Erle and Jo Walsh for their geocoding insight & software . Check out their free geocoding service and their mapping books. Other open-source GIS software utilized includes the Geospatial Data Abstraction Library and the GEOS Library.
This site would not be possible without the use of open-source software. My hat is off to Linus Torvalds and the developers of the GNU/Linux platform (specifically, Debian). Also, I would like to thank Guido van Rossum and associated developers for the Python programming language. Other software used in this site include the PostgreSQL database and the Perl programming language.
Thanks,
--The Houston Crime Master