When Algorithms Ensnare the Innocent

Michael Williams, a 65-year-old grandfather, sat in Chicago’s Cook County Jail for nearly a year after he was accused of shooting and killing a young man. The accusation was based on evidence provided by a network of surveillance microphones called ShotSpotter that is widely used by law enforcement across the U.S.

But after determining that there was insufficient evidence to keep Williams behind bars, prosecutors dismissed his case, undermining confidence in ShotSpotter, the gunshot detection firm that used artificial intelligence to evidence Williams’ supposed crime.

The case is an example of serious flaws in ShotSpotter, which prosecutors frequently use for evidentiary support, according to an Associated Press investigation.

From missing live gunfire right under its microphones to misclassifying the sounds of fireworks or cars backfiring as gunshots, ShotSpotter can convey serious inaccuracies, the AP found., adding that its inconsistency points to broader concerns about algorithm-based technologies used by law enforcement authorities.

In Chicago, the police department recently renewed its contract with the company until late 2023, disappointing activists who pushed officers to cut ties with ShotSpotter, Block Club Chicago reported.

Claiming the ShotSpotter improves response times for patrol officers by determining the location of loud noises, Chicago police have used the company since 2016.

But studies and anecdotal accounts have suggested that the tool doesn’t work as well as advertised, and contributes to overpolicing in non-white neighborhoods.

Some researchers also claim it has been manipulated at the request of police departments in criminal prosecutions.

A May study from MacArthur Justice Center at Northwestern University’s School of Law concluded the tool is too unreliable for routine use. Researchers found that ShotSpotter sent Chicago officers on more than 40,000 “dead-end deployments,” meaning officers never filed any kind of police report after responding to an alert, Block Club Chicago reported.

In addition to having “no significant impact on firearm-related homicides or arrest outcomes,” an April study found, ShotSpotter is “almost exclusively” used in non-white communities, according to Vice Magazine.

The same story showed the company has manipulated the data at the request of police departments, including Chicago’s.

Despite these serious findings, ShotSpotter continues to thrive.

Its share price has more than doubled since it went public in 2017 and it posted revenues of nearly $30 million in the first half of 2021.

The White House anti-crime agenda seems to endorse artificial intelligence systems. President Joe Biden has nominated David Chipman, a former ShotSpotter executive, to head the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).

Biden also encouraged mayors to use American Rescue Plan funds to buy gunshot detection systems, “to better see and stop gun violence in their communities,” NBC News reported.

Brendan Max, Williams’ attorney, requested a hearing in the coming weeks about whether to release ShotSpotter’s operating protocol and other documents the company wants to keep secret. The judge granted Max’s request, which could be used to cast doubt on the validity and reliability of ShotSpotter evidence in cases nationwide.

the ordeal has left Williams deeply shaken.

Returning to his neighborhood, he said he doesn’t feel safe in his home town anymore, constantly scanning for little microphones as he walks around.

“My client did not deserve to have his liberty taken away based on unscientific, unproven evidence,” Max told the AP.

“Given the history of flawed forensic evidence in our courts, we can’t let ShotSpotter be the next thing that racks up wrongful convictions.”

Eva Herscowitz is a TCR Justice Reporting intern.