ShotSpotter helps Cape police determine firework or gunshot

Cape Girardeau Police Department's gunshot detection system went live last month and is able to determine the difference between gunshots, fireworks or vehicles backfiring.

The high number of sensors throughout the city record sounds from a specific area and determine the source of a noise. It can then triangulate the location of the noise's source within a few meters. Cpl Ryan Droege of the Cape Girardeau Police Department said the sensors are placed in undisclosed locations throughout the city.

"These sensors can pick up noise and then analyze it to determine if it's a gunshot or a firework or a car backfire or any other loud noise," Droege said. "For example, it picks up a lot of noise from the train tracks, however, the system recognizes that they are not gunshots and does not alert us."

According to the ShotSpotter website, the company's technology, "helps local, state and federal law enforcement respond to, investigate and deter crime -- the platform is highly data-driven and includes community protections and engagement opportunities to help improve police-community relations" by deterring crime.

The department has had 35 detections by the system since the program began in May. When ShotSpotter detects gunfire in a predetermined area the audio is sent to ShotSpotter's review center and analyzed by a trained professional. Cape Girardeau Police Department, as the end user may also contact ShotSpotter to notify the company whether the sound was or was not a gunshot. The information provided by the police department to the review center allows ShotSpotter Inc. to refine its detections for future detection.

According to a previous article, ShotSpotter services a "1.2-square-mile area" and the process from the sound of a gunshot to a police dispatch takes approximately 60 seconds. The department has experienced very few issues with the system during the first month of its use.

"We have only just noticed a few issues this week, however this was anticipated as they [ShotSpotter Inc.] warned us that this is the hardest period of the year due to the immense amount of fireworks being discharged," Droege said.

Members of the Cape Girardeau Police Department plan to check response times to ShotSpotter notifications in the coming months. Information from the system is sent to Cape Girardeau 911 Communications Center and police officers's in-vehicle tablet.

ShotSpotter Inc. is based in Newark, California. In an article by the New York Times, public-safety specialist for ShotSpotter Inc. Scott Beisner said individuals can typically determine the auditory difference between gunshots and fireworks by listening to the cadence of the noises.

"When somebody pulls a trigger, they tend to pull it in a fairly steady rhythm until the end, when their finger gets tired," he said. "With fireworks you might have a small bang followed by a loud bang."

Today's hearing website states decibel levels for gunshots can range between 140 and 165 decibel and fireworks range from 150 to 175 decibel.