Trulia Crime Maps Bring Big Data to the Masses

Real estate website Trulia is set to roll out a new feature that will allow users to view crime statistics for 50 metro areas in the US.
The new feature, which is slated for launch in June, is a valuable exercise in large scale data processing. The crime maps are based on data collected from more than 1,000 different sources, aggregated into more than 5 million data points on the maps. Block-by-block crime density from the past 12 months is presented in heatmap form, with the top 5 percent of blocks with the most crime colored dark red, the next 5 to 10 percent in light red, and so on. The maps’ update rate varies from hourly to monthly, based on when each locations’ data is available from the various third-party agencies that work directly with law enforcement.
The crime map feature is made possible largely by Trulia’s December 2010 acquisition of geo-data aggregation startup Movity. Movity was part of Y-Combinator’s Winter 2010 class with the stated goal of giving home buyers information on what the location is “really like” by mapping data on noise and crime. Terms of the Movity buy were undisclosed.

The crime maps launch is evidence of Trulia’s rigorous engineering culture, CEO Pete Flint told reporters during a recent meeting at the company’s San Francisco headquarters. Trulia’s technologies are all developed by the company’s in-house U.S.-based engineering team, he said, while some of the Trulia’s competitors are said to occasionally outsource programming projects to third-party contractors. “Real estate listings are a commodity,” said Flint. “It’s the user experience and the information that accompanies [the listings] that makes it consumable.” That’s why Trulia, which is profitable, has made a concerted effort to reinvest a good portion of its revenues in keeping its technology as up-to-date as possible, he said.
Trulia’s feature may not seem groundbreaking to citizens of hyper-connected cities such as San Francisco, which is already served by Everyblock, a website which posts crime data and other local news overlaid on maps. But Everyblock is currently only available in 16 metro areas; Trulia’s crime maps will launch in 50 metro areas. In many places, Trulia’s crime maps could quickly become a unique and hugely valuable offering.