After installing video surveillance cameras around the city, Chicago’s murder rate plummeted to levels unseen in forty years. Now the police are hoping to cut crime not only by watching, but also by listening.
When a shot rings out, the city’s new technology recognizes the gun’s report within a two-block radius, directs the camera in the general direction, and dials 911.
Crime fighting joins the 21st century.
“Instead of just having eyes, you have the advantage of both eyes and ears,” said Bryan Baker, chief executive of Safety Dynamics LLC, the company in suburban Oak Brook that makes the systems.
Listening surveillance isn’t only catching on in Chicago, where thirty devices have been installed in crime-ridden neighborhoods in tandem with video cameras. Baker mentions that multiple installations are slated for the future.
Other city’s are purchasing the technology. The Los Angeles Country Sheriff’s department plans to test twenty listening devices, and the city of Tijuana, Mexico, bought 353 units, Bakers says. Law enforcement officials in Philadelphia and San Francisco are making plans to test the systems soon. Police from New Orleans and Atlanta have inquired as well.
The technology comes out of military applications. In Iraq, soldiers utilize similar technology. Developed in 2003 and 2004 by Defense Advanced Research Projects Agency in conjunction with BBN Technologies Inc., a sound detector called “Boomerang†is mounted on a vehicle, locating hostile gunfire.
The Safety Dynamics system employed in Chicago, formally known as Smart Sensor Enabled Neural Threat Recognition and Identification, abbreviated SENTRI, uses four microphones to triangulate the location of the gunshot.
The military’s Boomerang differs by actually detecting shock and sound waves from firing guns.
Cops in Chicago anticipate the SENTRI system to add to law-enforcement measures already deployed, further tightening the squeeze on illegal guns and gang violence.
The ACLU has expressed concern regarding privacy issues, and proponents of SENTRI listening systems insist that the units cannot be used to bug homes, or even recognize human voices.
