Denver police department using gunshot tech with "serious flaws"

AI-powered tech touted by the Denver Police Department and installed in more than 100 other cities across the country is under fire for failing to reduce gun violence and increase weapons-related arrests.

Driving the news: A new Associated Press investigation calls out "serious flaws" in using ShotSpotter — a network of sensors installed on telephone poles or streetlights that detects gunshots and alerts police officers — as a reliable public safety tool.

• The report — based on thousands of documents and dozens of interviews with public defenders in cities where ShotSpotter is used — found the system can overlook live gunshots "right under its microphones" and fire off false alarms when other loud pops, like fireworks or cars backfiring, happen nearby.
• Some judges have thrown out ShotSpotter evidence, and some who haven't have mistakenly put people in jail, the AP reports. People of color tend to be at most risk of being unfairly targeted, because the system is typically placed in crime hotspots, often disproportionately Black and Latino communities.
• ShotSpotter is also expensive — annually costing cities up to $95,000 per square mile. Researchers have determined policy solutions may prove a more "cost-effective" route to reducing gun violence.

Why it matters: The investigation comes weeks before Denver's city budget negotiations shift into high gear.

• Mayor Michael Hancock, a vocal supporter of city police, will present his proposed 2022 spending plan to the Denver City Council by Sept. 16, his spokesperson Mike Strott tells Axios.

By the numbers: Denver's contract with ShotSpotter costs $835,438 a year, according to DPD.

• Since the agency first implemented the technology in 2015, taxpayers have paid roughly $6 million to foot the bill.

Meanwhile, gun violence continues to soar.

• Homicides are up 50% over the three-year average, Denver police chief Paul Pazen said at a news briefing last month.

Yes, but: A 2019 Urban Institute study found that gunshot detection technology can be a "powerful tool" that helps prosecutors and police better keep communities safe.

• Still, researchers suggest its effectiveness depends on a combination of tools and practices, along with "authentic partnerships" with neighborhoods most impacted by violent crime.

What they're saying: DPD maintains ShotSpotter is a "valuable tool … to speed police response to gunfire, locate gunshot victims and physical evidence, and provide investigators with information," including the number of shots fired, the agency told Axios in a statement.

• "It’s important to note that ShotSpotter is just one tool among many used by DPD in conjunction with comprehensive investigative processes," the agency said.

What to watch: Denver City Council, some of whose members remain interested in defunding the police, have the final say over Hancock's budget. They will vote on it by mid-November.