Gunshot Detection Technology

[DonMoose 3]

Officials in Mount Vernon and Yonkers are hoping that $3 million worth of sophisticated sound and video technology provided by Westchester County will help cops use the sound of gunfire to their advantage.

County Executive Andy Spano today announced that the county will buy and install a network of sound sensors in both cities that can detect gunfire, pinpoint its location and relay the information to police within seconds.

http://www.lohud.com/article/20090312/NEWS02/903120492

Found this interesting...I wonder what the rate of false alarms would be due to cars backfiring, or other similar sounds. Anyone have any additional information on how the system works?

Edited March 13, 2009 by DonMoose

[helicopper 1,050]

Excerpt of a report by Lorraine Green Mazerolle for the National Institute of Justice (NIJ), full report available from their website.

Researchers used a test area in Redwood City, California, to determine the accuracy of Trilon Technology's ShotSpotter System. ShotSpotter uses a triangulation algorithm to pinpoint the location of the apparent gunfire and allows users to replay the sound of the gunfire noise. The test area covered

about 1 square mile, which was divided into 319 sectors, each identified as either a "hot spot" (one with a relatively large amount of gunshot activity) or a "cold spot" (one with a relatively small amount of gunshot activity).

On June 26 and 27, 1997, blank rounds were fired at 32 locations--22 hot spots and 10 cold spots--using one of three weapons at each site: an MP-5 assault rifle, a .38 caliber pistol, and a 12 gauge shotgun. (Note that blank shots are much more difficult to detect than live ammunition.)

The researchers determined that the ShotSpotter accurately detected 80 percent of the shots fired in the field test; 72 percent of the shots were also triangulated, with a 25-foot margin of error in pinpointing the exact location of the gunshot. The type of weapon fired affected the system's ability to detect the shot: The MP-5 rounds were much more difficult for the system to detect than either the pistol or shotgun rounds.

What impact do gunshot detection systems have on police response times?

Researchers conducted a 2-month field trial (October 25-December 16, 1996) of the System for Effective Control for Urban Environment Security (SECURES), developed and manufactured by Alliant Techsystems, --in the Oak Cliff neighborhood of Dallas, Texas. As in Redwood City, the test area was about 1 square mile. Eighty-six SECURES units were installed on poles in the test area, primarily at intersections. Police response times to technology-generated reports of gunfire were compared to response times to citizen-generated reports both before and during the test period. For the most part, there was little difference

between response times to technology-generated reports of gunfire during the test period and response times to citizen-generated reports before the test

period.

More recent info...

During the 1990s, Boston's Operation CeaseFire demonstrated phenomenal success in reducing youth gun violence.

During the current decade, law-enforcement officials have begun using new technology to determine where and when gun violence may be taking place. In 2001, under the lead of Mayor Joe Riley and former Police Chief Reuben Greenberg, Charleston, S.C., launched Project CeaseFire, its own comprehensive gun enforcement initiative. In addition to its other provisions, this program used a then-novel technology to identify the location of gunshots. More recently, the same sort of system was set up in Chicago, where gunshot detectors were located in 80 gang-ridden neighborhoods.

"It's a wonderful new tool and the criminal element should be worried."

-- Mayor Joe Riley, Charleston, S.C.

Gunshot-detection technology relies on acoustic sensors deployed in public places (such as telephone poles) and a "triangulation" system to narrow down the possible location of the shots. When the sensors detect a gunshot, a transmitter sends that information to the police department. The gunshot's location appears on a computer map, and within seconds a police dispatcher can send a unit to respond. If there is any question about verifying the gunshot, a six-second recording of it is available for the police to review.

This technology, known as ShotSpotter, is not foolproof, but it has become more reliable. The real promise of these systems lies not just in a quicker police response; but in the possibility that they can help authorities develop and implement strategies for reducing gun crimes in targeted areas.

<excerpt>

Police in one New Jersey city are hoping to rely less on sketchy reports of shots fired and more on technology that uses acoustic sensors, radio frequencies and triangulation to pinpoint the location of gunfire. Police in East Orange announced the installation of SECURES Gunshot Detection System this week. A half dozen other cities are using the technology. Most are applying the technology in a covert manner and have requested non-disclosure, according to George Orrison, director of marketing security technologies for Planning Systems Incorporated.

Planning Systems Incorporated, of Reston, Va., provides battery operated sensors that can distinguish gunshots from other city sounds, including engine backfires and fireworks. The sensors, produced using ISO 9001:2000, are housed inside gray boxes.

The standard system includes at least 100 sensors, for one square mile. Sensors are generally located at every intersection. They can be mounted on utility poles, street lights and buildings.

Individual sensors transmit small data packets to a receiving unit with an RF antenna. The system tags the time and date. Once several sensors have relayed the information, the differences in arrival time are used to triangulate the location of the gunshot.

Within five seconds, a flashing icon displays the location and nearest street address on a GIS map. The wireless, portable, IP-based system, allows access and monitoring by dispatchers inside police stations, by officers in patrol cars, from aircraft, and via handheld devices.

Johns Hopkins Tests Gunshot Detection System

By Dian Schaffhauser

12/04/08

<excerpts>

The system relies on 93 sensors installed on city-owned streetlights and Johns Hopkins off-campus buildings. The sensors automatically detect a gunshot's acoustic signature and transmit related information wirelessly to a receiving station. That detection information is then forwarded within three to five seconds over a secure network connection to the communication center. At the center, the gunshot location is displayed on a 40-inch LCD screen with an alert indicating the nearest address and building for dispatch.

The sensors include technology that can differentiate gunfire from fireworks or vehicle backfire. A series of gunshots could indicate a running gunman and the SECURES system would track the direction of his travel.

[Guest alsfirefighter]

Good posting Chris. I wonder what it is with the difficulty of picking up the MP-5 shots? I know its slightly muffled and you hear more of the action cycle when firing when compared to the normal pop of a pistol...but maybe with the longer barrel and the use of the standard 9mm pistol round changes the acoustics?

Very interesting system. I just hope the county has a plan for long term maintenance because once the system has a problem all it will do as most municipalities that take such things with funding and they break...sit there as there will be no funding for repair.

[ny10570 745]

I read a report on these I think out of Dallas. They were getting officers on scene by the time calls were coming into the system. They also found the system was more accurate than callers with fewer false alarms and better locations. Triangulated location of the shot rather than the various caller locations.

[Just a guy 493]

I think it will be a great tool for us to use.. anything that will allow us to respond faster is better !!!

[RWC130 594]

Saw a clip about it on News12 last night. Looks very interesting

and hopefully will have a positive impact on crime in Mount Vernon

and Yonkers.

[Oswegowind 17]

I think it will be a great tool for us to use.. anything that will allow us to respond faster is better !!!

Hopefully you will get descriptions too...as long as they are relayed...oooops!