Garance Burke and Michael Tarm broke the news that gunshot-detection company ShotSpotter gives its human reviewers broad discretion to overrule an artificial intelligence-powered law enforcement tool’s determination about whether something is a gunshot. The exclusive came after Burke, an investigative reporter in San Francisco, obtained a confidential ShotSpotter document. The document provided a unique window into the company whose data is sent to police and used in criminal cases nationwide.

Burke and Tarm, a Chicago-based legal affairs writer, worked together for three months to deepen their reporting around the document, including consulting with gunshot detection experts and reading studies and court filings. Tarm interviewed audio experts and found a court transcript in which a ShotSpotter employee told a judge the company likes to hire musicians as reviewers because they “tend to have a more developed ear.”

The story generated hundreds of thousands of views on Twitter and was picked up by The Washington Post, Chicago Sun-Times and other media outlets. Officials and citizens in several places where ShotSpotter operates said they planned to raise the story’s findings in city council meetings to question the company’s high-tech claims.