Chicago won’t renew its ShotSpotter contract and plans to stop using the controversial gunshot detection system later this year, Mayor Brandon Johnson’s office announced Tuesday.

The system, which relies on an artificial intelligence algorithm and network of microphones to identify gunshots, has been criticized for inaccuracy, racial bias and law enforcement misuse. An Associated Press investigation of the technology detailed how police and prosecutors used ShotSpotter data as evidence in charging a Chicago grandfather with murder before a judge dismissed the case due to insufficient evidence.

Chicago’s contract with SoundThinking, a public safety technology company that says its ShotSpotter tool is used in roughly 150 cities, expires Friday. The city plans to wind down use of ShotSpotter technology by late September, according to city officials. Since 2018, the city has spent $49 million on ShotSpotter.