DENVER — An alert from Denver’s gunshot detection system prompted police officers to swarm a Montbello woman’s 70th birthday party with guns drawn and detain Black partygoers for close to an hour — even though the ShotSpotter alert was 20 minutes old, for a neighboring address and was likely triggered by fireworks, according to a new lawsuit.

The two dozen or so people at Augusta Horton’s home in the 5100 block of Crown Boulevard on the evening of April 13, 2024, told Denver police officers that no one had fired any shots around them and that their neighbors were setting off fireworks, but the officers nevertheless detained the partygoers — at times at gunpoint — and forced them to submit to unlawful searches, according to the complaint filed in Denver District Court on Monday.

A Denver Police Department spokesman did not immediately return a request for comment Wednesday. The lawsuit names the city and 11 Denver police officers as defendants.

The city’s ShotSpotter system is a network of sound-detection sensors that pinpoints the location of gunshots and sends alerts to police.

The system can also be triggered by sounds like fireworks, car backfires or construction noise and has been criticized for focusing police attention on low-income communities with non-white residents.

The guns-drawn response to Horton’s birthday party violated the Denver Police Department’s own training on how officers should respond to ShotSpotter alerts, the lawsuit alleges.

Officers are trained to approach the area of a ShotSpotter alert without drawing their weapons, and are instructed to start such calls by asking questions of people in the area. Officers are supposed to leave if they do not find evidence of gunfire, like shell casings, injured people or witness reports, according to the complaint.

The ShotSpotter alert at 7:29 p.m. on April 13, 2024, referenced two shots at the address next door to the Hortons’ house, according to the lawsuit. The first officers arrived about 10 minutes after the alert and immediately zeroed in on the Hortons’ home, where about two dozen Black people were gathered for the birthday party.

Police watched the home for another 10 minutes before the first two officers approached the party with their guns drawn. One officer pointed his gun at the group, and both officers demanded the partygoers put their hands in the air, the lawsuit alleges.

One officer said he approached the home because he “saw a big group of people,” and didn’t “know if one of y’all shot it off,” according to the complaint, which cites the officer’s body-worn camera footage. Another officer said he saw a “(expletive)-ton of people right in the circle,” apparently referencing the area of the ShotSpotter alert.

“This statement reveals the officers’ reasoning: not that any individual was suspected of wrongdoing, but that the mere presence of a large group of Black people at the location of a ShotSpotter alert — an alert that pointed to a different address — warranted a weapons-drawn mass detention,” the lawsuit reads.

Horton and her guests told the officers that their neighbors were using fireworks, and the sound of fireworks is heard on the officers’ body-worn camera footage during the call, according to the complaint.

The officers kept the partygoers detained for nearly an hour, with additional officers arriving over that time, until a supervisor arrived and ordered the officers to leave, the lawsuit said.

The police department refused to release body-worn camera footage of the incident for more than 18 months, attorneys Edward Hopkins and Raymond Bryant wrote in the complaint.

The lawsuit raises claims of unreasonable searches and seizures and failure to intervene, as well as claims related to the police department’s initial refusal to release records related to the incident.

----------

©2026 MediaNews Group, Inc. Visit at denverpost.com. Distributed by Tribune Content Agency, LLC.