A Seattle City Council committee hears about a technology designed to help police locate the source of gunshots.

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The city of Seattle is considering placing sensitive microphones throughout parts of the city that would help police pinpoint gunfire.

City Councilmember Bruce Harrell, who chairs the Public Safety, Civil Rights and Technology Committee, said on Thursday that data from so-called “automated gunshot recognition systems” could help police aim resources at high-crime areas and give the department a better idea of the actual amount of gun violence in the city.

Seattle has seen a surge in gun violence, with 20 of the near-record 22 homicides so far this year attributed to gunfire. Among those killed were five people who died in a May 30 shooting spree that ranged from Cafe Racer, an artsy coffee shop in the University District, to West Seattle, where the shooter killed himself as police closed in, and the May 24 death of a software engineer who was struck by a stray bullet while driving with his parents on East Cherry Street.

Mayor Mike McGinn has called the surge in gun violence a public-safety emergency, and both state and federal law-enforcement agencies are focusing on getting armed felons off the street.

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Police officials and Harrell say the amount of gunfire in the city is likely significantly underreported, often because people don’t call 911.

When shots are reported, officers often can’t prove shots were fired without a victim or other evidence, such as shell casings or property damage.

Several large cities, including Chicago, and New Jersey and Los Angeles County have turned to the gunshot-locating technology, which vendors say can pinpoint gunfire to a specific address, tell police how many shots were fired, whether they were fired from a large- or small-caliber weapon, and, in some cases, even what direction the shooter is heading. It does this by measuring tiny differences in the time it takes for the sound of the shot to reach a series of microphones, and then software is used to triangulate the point of origin.

On Thursday, Harrell’s committee heard the presentation of one vendor, ShotSpotter, of Mountain View, Calif., which has suggested setting up a trial system in three areas covering roughly 15-square miles in south and Southwest Seattle. The areas include Rainier Valley, parts White Center and West Seattle.

ShotSpotter would lease the equipment to the city for between $40,000 and $60,000 per square mile, with a minimum coverage of three square miles. The cost would include providing a manned dispatch center that would relay information when shots were fired to SPD dispatchers or directly to the officers on the beat.

Ralph Clark, the company’s president, told Harrell’s committee that 70 cities currently use the system and that data from Oakland, Calif., and elsewhere have shown that as few as one in five incidents of gunfire is reported.

Over 30 days, he said the system was able to map more than 600 instances of gunfire in Oakland, when only a fraction of that number had been reported to police. The company says the system has a deterrent effect and can be used in prosecutions.

Another developer of gunshot-location technology, Safety Dynamics, has a similar system that the city could purchase, rather than lease, at a cost of roughly $192,000 per square mile.

Harrell acknowledged that with either system, installation throughout the entire city would be cost-prohibitive.

Los Angeles County, Clark said, has installed the technology in areas with high crime and low reporting rates.

Assistant Police Chief Paul McDonagh told Harrell’s committee that data from the system could be used by the department to allocate resources to hot spots; however, he cautioned that it could also be a drain on those same resources as they respond to additional calls.

Deputy Police Chief Clark Kimerer said the department will also have to weigh the cost of such a system against other needs in a year when the city is facing a nearly $30 million budget shortfall.

Mike Carter: 206-464-3706 or mcarter@seattletimes.com

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