Fighting Crime From Above?

Two years ago, the city of Dallas started installing public CCTV cameras.  Today the total camera count is 96.  Two weeks ago, Mayor Pro Tem Elba Garcia stated,  "Cameras have helped reduce crime in such a dramatic manner that we are victims of our own success".

This pro-camera statement is not out of the norm for politicians.  A politician manages people who report to them, and generally trust what they say is accurate. 

So is this statement from the Mayor accurate?  Scott Henson of Pegasus News has raised an eyebrow.

Scott points out that there is a pre-existing trend of crime declining as well as a change in burglary reporting.  He questions whether these items were taken into consideration during the analysis.

There aren't a lot of CCTV effectiveness studies in the U.S., and the closest one that can be comparable may be that of San Francisco.  In 2008, the San Francisco city council commissioned UC Berkeley to write an effectiveness report on their 19 public cameras.  This report can be found here.  To synopsize all 184 pages, there was no evidence that the cameras were effective.  

To perform a legitimate analysis of the effectiveness of the Dallas camera initiative, I recommend the city defines proper control groups and measure for displacement and diffusion of benefits.  It is also important to categorize the 1700 arrests, and break them down by: murder, rape, robbery, felonious assault, burglary, grand larceny, and auto theft.  If the crimes don't fall under a "CompStat major crimes" category, it's important to state what categories of crimes they are (i.e. vandalism).   It's also important to tell the reader how many pre- and post- data points were used as well as methodology adopted and why.  Lastly, don't forget peer review. 

If the Dallas Police Department stays in the CCTV business, I recommend they follow my guidelines for surveillance system effectiveness reporting.  It's not overly onerous, and won't cost the taxpayers $1,000,000 a year to maintain.

So is the City of Dallas really a victim of their own success as the mayor claims? If so, they should release an effectiveness report so the public can read it and other cities can learn from their model.