Questions Raised About Accuracy of ShotSpotter Gunshot Detection

A report by a Chicago watchdog agency claims ShotSpotter is ineffective, but the company says its solution is 97% accurate.

CHICAGO — After spending tens of millions of dollars on ShotSpotter, a gunshot detection system, research from a Chicago watchdog agency says the technology rarely produces evidence of gun-related crime in the city.

In the report, the Office of Inspector General’s (IOG) Public Safety section said that between Jan. 1 2020 and May 31, 2021, more than 50,000 ShotSpotter alerts were confirmed as probable gunshots, but only about 4,500 of those incidents resulted in gun-related crime, reports ABC News. Chicago’s Office of Inspector is a taxpayer-funded independent watchdog that has subpoena power but no authority to change or eliminate city programs.

According to an Associated Press investigation, the system is flawed, missing live gunfire right under its microphone and misclassifying the sound of backfiring cars and fireworks as gunshots. Further, judges involved in a number of court cases have thrown out evidence from ShotSpotter.

The report says the use of ShotSpotter changes the way Chicago Police Department (CPD) officers respond to calls and is being used to form the basis of investigations.

“If the Department is to continue to invest in technology which sends CPD members into potentially dangerous situations with little information—and about which there are important community concerns—it should be able to demonstrate the benefit of its use in combatting violent crime. The data we analyzed plainly doesn’t do that.”

The recent IOG and AP reports, as well as several court cases, have lawmakers questioning whether the technology should continue to be funded and if it contributes to racial bias in law enforcement.

Still, Chicago plans to continue to use the system, having received an extension of its three-year, $33 million contract with ShotSpotter. Chicago Mayor Lori Lightfoot called the technology a lifesaver, especially when paired with cameras and high-tech support centers.

ShotSpotter has responded by saying that an independent audit of the system shows its accuracy at 97% based on feedback from more than 120 customers. On Medium, ShotSpotter CEO Ralph Clark said the recent concerns have been presented by advocates and reporters “with poor understandings of police data and inept analyses” and they have “used classic, misleading rhetorical tricks to falsely portray ShotSpotter technology.”

Clark said,”… expert human reviewers — not some mysterious, secret algorithm — decide whether or not to publish gunfire alerts to police.” He also claims the data was cherry picked.

He further cited success stories involving the company’s technology, including:

  • In Oakland, California, 101 gunshot would victims were found and aided by police due to a ShotSpotter alert when no one called 911
  • Pittsburgh, Pennsylvania reported a 36% drop in homicides
  • Greenville, North Carolina reported a 29% decrease in gun violence injuries the first year ShotSpotter was deployed.

This article first appeared in SSI sister publication Campus Safety.

If you enjoyed this article and want to receive more valuable industry content like this, click here to sign up for our FREE digital newsletters!

About the Author


Robin has been covering the security and campus law enforcement industries since 1998 and is a specialist in school, university and hospital security, public safety and emergency management, as well as emerging technologies and systems integration. She joined CS in 2005 and has authored award-winning editorial on campus law enforcement and security funding, officer recruitment and retention, access control, IP video, network integration, event management, crime trends, the Clery Act, Title IX compliance, sexual assault, dating abuse, emergency communications, incident management software and more. Robin has been featured on national and local media outlets and was formerly associate editor for the trade publication Security Sales & Integration.

Security Is Our Business, Too

For professionals who recommend, buy and install all types of electronic security equipment, a free subscription to Security Sales & Integration is like having a consultant on call. You’ll find an ideal balance of technology and business coverage, with installation tips and techniques for products and updates on how to add sales to your bottom line.

A free subscription to the #1 resource for the residential and commercial security industry will prove to be invaluable. Subscribe today!

Subscribe Today!

Leave a Reply

Your email address will not be published. Required fields are marked *

Get Our Newsletters